How many exactly? Do you have concrete data?

My understanding is that the vast majority of the homeless in NYC do sleep in shelters because... well, NYC has plenty of shelters.

That's also what a comment above notes, quoting an SFBay article[0]: 67% of Bay Area homeless are unsheltered, 5% in NYC.

So there might be a small number of homeless folks who can't / won't live in shelters, but that's what it is: a small minority.

[0] https://www.sfgate.com/bayarea/article/Bay-Area-homeless-uns...

Hundreds of shelter beds go empty every night in LA because many of the homeless would rather stay high/drunk than be sooner for a night. They used to be a small portion of the population but now comprise the bulk of LAs skid row population.

Could criminalize sleeping on the streets if beds are available at a local shelter.