There’s too much money invested in NYC to allow Manhattan to go the way of Detroit. Regardless of the imaginations of many on FR, it’s not going to happen.
What you will see is a further deterioration of the other four boroughs. Much of Brooklyn and the Bronx are horrible already, but the trend had been that improvement waa coming to those areas. That trend will be stymied, and likely reverse a bit.
NYC won’t be a new detoit, though. That’s just a popular conservative fantasy.
Correct.
The Mahattan and Stantan Island parts of NYC will stay the same. The rest of the city as you have said will go down hill.