I thought of a few answers to this difficulty:

There is a passage that speaks about a possible mode of divine hiddenness:
14 And the Lord said to Moses: Behold, your days draw near that you must die; call Joshua and present yourselves in the Tent of Meeting, that I may charge him. And Moses and Joshua went and presented themselves in the Tent of Meeting. 15 And the Lord appeared in the Tent in a pillar of cloud, and the pillar of cloud stood over the entrance of the Tent. 16 And the Lord said to Moses: Behold, you are about to lie down with your fathers, and this people will rise up and go astray after the foreign gods of the land into which they are going among them, and they will forsake Me and break My covenant that I have made with them. 17 Then My anger will be kindled against them on that day, and I will forsake them and hide My face from them, and they shall be devoured, and many evils and troubles shall come upon them, so that they will say on that day: Have not these evils come upon me because my God is not in my midst? 18 And I will surely hide My face on that day because of all the evil they have done, for they have turned to other gods. 19 Now therefore write this song for yourselves, and teach it to the children of Israel; put it in their mouths, so that this song may be a witness for Me against the children of Israel. 20 For when I bring them into the land that I swore to their fathers, flowing with milk and honey, and they eat and are satisfied and grow fat, then they will turn to other gods and serve them and provoke Me and break My covenant. 21 And when many evils and troubles come upon them, this song shall testify before them as a witness, for it shall not be forgotten from the mouths of their descendants; for I know their inclination, what they are doing today, before I bring them into the land that I swore.

One can understand that this mode of hiddenness is not only a temporary mode for a period of sin, but that from the moment Israel sinned, the mode of governance changed permanently to one of hiddenness. The Holy One, blessed be He, foresaw this in advance, and therefore also asked that the song be written forever so that despite the hiddenness, the covenant would still be preserved through the writing of the Torah.

Another answer to the difficulty:

If you pay attention, you’ll see that the flow of the Torah in the verses you brought begins in the previous chapter, Leviticus 25:1, where the Torah says:
1 And the Lord spoke to Moses at Mount Sinai, saying: 2 Speak to the children of Israel and say to them: When you come into the land that I give you, then the land shall keep a Sabbath to the Lord.

The following sections are attached to that speech. The word “when” here is used in the sense of “when you come into the land.” In other words, when you come into the land. The speech is relevant to the time when all Israel dwell in their land there (see Maimonides at the end).
As proof, you can see that many commandments given in the verses in this area are commandments dependent on the land: the Sabbatical year, Jubilee, redemption of land. Nowadays it is known that these commandments do not apply on the Torah level, because not all Israel dwell in their land. Similarly, the mode of divine governance that the Holy One, blessed be He, promised in these verses also does not apply nowadays, at least until those commandments once again apply on the Torah level. See also what Maimonides writes regarding the condition of dwelling in the land:

10:10 [8] Once the tribe of Reuben, the tribe of Gad, and half the tribe of Manasseh were exiled, the Jubilees ceased, as it is said, “And you shall proclaim liberty throughout the land to all its inhabitants” (Leviticus 25:10) — at a time when all its inhabitants are upon it; and this is only when tribe is not mixed with tribe, but all are settled in their proper order.

10:11 When the Jubilee is practiced in the land, it is practiced outside the land as well, as it is said, “It is a Jubilee” (Leviticus 25:10; Leviticus 25:11; Leviticus 25:12) — in every place, whether the Temple is standing or not. [9] And when the Jubilee is practiced, the law of the Hebrew slave applies, and the law of houses in walled cities, and the law of dedicated fields, and the law of hereditary fields, and resident aliens are accepted; and the Sabbatical year applies in the land, and release of debts applies everywhere — by Torah law.

10:12 And when the Jubilee is not practiced, the Hebrew slave does not apply, nor houses in walled cities, nor hereditary fields, nor dedicated fields, and resident aliens are not accepted; and the Sabbatical year applies in the land by rabbinic law, and likewise release of debts everywhere by rabbinic law, as we explained.

Rabbi, regarding the prophets: I don’t recall that the Holy One, blessed be He, made a contract and covenant with us in which He said He would send us prophets. I don’t see room for the comparison. As for miracles, I actually do believe there are miracles every day. As far as I’m concerned, the whole Torah simply loses its flavor the moment you take reward and punishment out of it. It was written like a contract: do such-and-such, and I will reward you with such-and-such. So you need a very, very strong justification to explain why you think this agreement expired, because that’s a bit like saying, from my point of view, that Judaism itself has expired.

Oren, your response actually sounds more reasonable. I’ll need to look into it more deeply. Thanks

The contract was signed in blank, before we saw it: “We will do and we will hear.” Its content was a commitment to observe the Torah, and there was no promise of reward in exchange. The promises were given to us in the Torah, so we only saw them after we had “signed.” So this is not an obligation, but a description of policy. But policy can change. I gave you a few examples, out of hundreds and thousands of course, of verses that say things and we interpret them against the plain meaning without having a verse to support that. Therefore the claim that there is no verse telling us about a change in policy is irrelevant.

By the way, some of the examples do speak about promises: blessing in the seventh year, for example. “Tithe, so that you may become rich” (“test Me now with this”). Do you think all of these are fulfilled?

You said that you think there are miracles. Open miracles too? In the past there were open miracles as well. Is there a verse explaining that open miracles will end? So what then? Why do I need a verse? It is simply a fact. And the same applies here.

Do you really see a clear correlation of rain with good deeds, as promised in the verses? I’d be happy to see the data you have. That could be quite a sensation.
And while we’re talking about promises, what about: “If you walk in My statutes,” or “like an eagle stirring up its nest,” and the like. Were the Egyptians murdered in the Holocaust and throughout the generations, or was it specifically Jews?
If you claim that the promises are being fulfilled, I don’t think you can bring facts that support that. At most you’ll have forced excuses.

Rabbi, I seem to remember hearing that “tithe so that you may become rich” — some say that this is talking about the second tithe. (A fifth.)
Does the Rabbi perhaps remember something about this?

By the way, I don’t understand the person who asked this, and all I can do is quote the words of Moshe Rat in Shabbaton in his commentary:
http://www.sofash.co.il/%D7%A9%D7%91%D7%AA%D7%95%D7%9F.html
(p. 34)
Not to ignore the curses
The curses in the section of Ki Tavo, like those in the section of Bechukotai, are customarily read in a low voice and quickly. It is not clear what the reason for this is. It may be that this expresses our fear of the curses, to the point that we do not dare articulate them aloud. It may be that people simply want to “spare” the congregation the unpleasantness of hearing descriptions of horrors. There are various customs according to which it is specifically the rabbi or another Torah scholar who is called up to the Torah for the reading of the curses, lest one suspect that he is directing their reading against his personal enemies.
I do not intend to come out against the custom of reading them quietly. But on the level of principle, perhaps it would have been proper specifically to read these curses aloud. For what is the purpose of the curses? To instill awe and fear in our hearts, so that we understand what severe consequences may result from our sins, Heaven forbid. If we “rush through” them quietly, then we are like a sick person who does not wish to listen to the doctor’s warnings about the grave harm that will be caused to him if he continues neglecting his health.
“Ugh, why is this doctor using scare tactics?” that patient grumbles. “Why can’t he present a warm and inclusive medicine that accepts me as I am and doesn’t demand that I change?”
It really isn’t pleasant to hear frightening descriptions, but ignoring them will not prevent them from being realized in reality; on the contrary — precisely paying attention to them, and the shock they awaken in a person, is what can save him.
The blood-soaked history of our people teaches us that God really did mean these warnings with full seriousness. These are not parables or exaggerations, but descriptions that were fulfilled again and again throughout the history of Israel. And if anyone imagined that God changed over the thousands of years, that in the modern era He is no longer so “strict” and “harsh” but is now all love and acceptance and tolerance — the Holocaust came and taught us otherwise. “For I the Lord do not change, and you, children of Israel, have not been consumed.” God has not changed, the Torah has not changed, and the harsh warnings are still in force.
Sometimes I wonder what we will really answer on the Day of Judgment, when God asks us why we learned no lesson from the two previous destructions. Why, after returning to our land, do we defile it with Sabbath desecration, promiscuity, pride parades, wrongs between man and his fellow, and other sins, just like the previous times. What will we say? That we thought He didn’t really mean it? That this time it was okay? “And He, being compassionate, forgives iniquity and does not destroy”