NY fell off because they couldn't write good songs once the r&b singer hook thing phased out (besides 50), and because the city stifled the club/venue scene while ATL/LA/Midwest/etc didn't have that problem. Their radio was also run by guys who deliberately refused to play NY artists. I also think a lot of their artists struggled to appeal to east coast dudes who expect you to look/sound like Nas/Jay/etc or else. Joey Badass managed to pop because he brought in some alternative black kids, white kids and a looooot of chicks. Same with ASAP. Whereas a lot of the NY shyt I fukked with at the time (Roc Marci, AG The Coroner, Maffew Ragazino, etc) didn't appeal to those groups, and they weren't fly enough for a lot of NY brehs.
I doubt we'll ever see a big NY (dude) rapper again.
Those aren’t the only reasons.
Another reason is that new NYC producers are very one note. So the sound didn’t transcend the way it was supposed to. Drill was a good transition but drill gets dry fast bc all the drill producers sound the same. The best drill producer is from the UK
The other reason is the NYC OGs of Hip Hop won’t pass the crown to younger generation because they were too busy still rapping themselves. So the youth did it themselves and represented a new New York that the older people don’t like. Which causes an age divide.
This doesn’t happen in the south or west
Kendrick was immediately embraced by Game, Dre, Snoop, etc
ASAP Rocky was getting shytted on by the NYC elder statesmen initially