God's intervention in the world versus existing evil

Hello Rabbi!
For a long time now, I've been bothered by a very difficult question, and every answer I get feels irrelevant.
I will state the general understandings:
I had a hard time with the "problem of evil" in the world. How can there be so much evil in the world if God is all good? The answer of "you don't know the calculations of heaven" sounds evasive to me, because for example, in the events of the last war or the Holocaust, there were horrors that are unthinkable or acceptable as good in any way. In addition, saying that everything is part of a good plan brings up a question in itself: If God is omnipotent, why does one have to go through horrors like even children dying in order to achieve good? After all, being omnipotent means that He can also achieve good without the bad part…
The answer to this question that really made a bit of sense to me was precisely the words of Maimonides in the Teaching of the Perplexed, according to which a person has free choice to choose between good and evil, and therefore the evil that exists in the world is either because of the freedom that a person has or because of the laws of nature that simply exist, and there can be something in nature that is not good.
But my question is this:
If that is indeed the case, then surely one of the explanations for prayer is a request. Besides the fact that prayer is essentially connecting with God, it is of course also a request. We see many times in the Sages that they prayed and received what they asked for. This matter is difficult for me at first because many times I make maximum efforts on my part and pray and yet it is not answered. But beyond that, if God does not intervene in the world, how can I ask Him to fulfill a specific request for me? After all, I am actually asking Him to intervene in the world! And if He intervenes in the world through prayer, how can things like the Holocaust, for example, happen? After all, people back then certainly prayed with all their might and still have 5 years of atrocities…
Additionally, if God is omnipotent, does that mean that He can also make a free choice without there being evil? After all, omnipotent means truly omnipotent, even if it sounds to us as illusory as impossible, so that a world in which there is free choice without evil can still come to mind. And to say that He created the world in the most perfect way (so that bad disasters are part of good) is an evasive answer because He can create a perfect world without evil, because again, He is omnipotent…
I am very confused, Rabbi. I would be happy if the Rabbi could answer me.
Thank you very much!