The problem of NYC being unaffordable is due to there being too many people who want to live in NYC and too little NYC. The only thing he can do about that is make it so that no one wants to live in NYC. He may well succeed.
You’ve identified the key issue here, beef. What is also going to happen is that the place will become a magnet for those seeking to collect on all of the promised freebies, add in the illegals he has promised to protect, and we’ll see where this goes.