When I looked into Christianity, I saw that the New Testament says that Jesus performed miracles before the eyes of thousands of people. Shouldn’t that be a compelling reason for a person to abandon Judaism over it? Why does the Rabbi see no need to address that?

If that seems credible and reasonable to you, then go and be a Christian. What exactly am I supposed to say about it?
In my assessment, that Christian tradition is not reliable, because he wasn’t even a public figure on that level during his lifetime, and there is no indication that what is told in that book really happened. But whoever believes it can be a Christian. I have no argument with him, and there is nothing there for me to refute.

In every religion, as far as I know, miracles were performed before the eyes of thousands of people. The uniqueness of Judaism is that the thousands of people before whom the miracle was performed are not anonymous; rather, we have testimony from an entire people whose forefathers were there, and because of that miracle (the revelation at Mount Sinai) the entire people is bound by a rigid system of laws different from the rest of the world. That is why the story of Judaism is credible.

This has already been discussed here several times. I’m not familiar with another example of a mass miracle, and certainly not one with a stable tradition about it. People talk about such things, but when you examine them further you discover that it’s really not the same thing. This has already been discussed on the site, and you can search for it.

Ro, take a look at the article at the Yedaya Institute.
By the way, we have no shortage of rabbis on our side who performed miracles.