Lots of crime and cities not thought to be attractive places to live. Crack is often cited as the main driver of urban decay but there myriad reasons cities like nyc began a decline in the late 60’s until the early 90’s when cities began to be sought after again.

What happens is as the tax base leaves the city has less money to take care of itself leading to more people leaving, etc. The opposite happens as people move back in.

I’d never count NYC out but it was clearly in need of a correction. After the riots and the regime in charge supporting it, the increase in muggings and robbery, and the blandness to much of what Manhattan has become, I know a few people that left. Especially with remote work being more viable.