Buildings with modern working sprinkler systems are rarely an issue for firefighters. As for break-ins the concierge rarely let roving bands of hooligans in to trash places / squat.

Empty luxury condos are not the fire / squat hazard that abandoned warehouses, etc are. Nice try.

It's pretty likely that someone would notice a squat in a luxury condo.

As for city services the NYPD could probably greatly improve their budget by not unconstitutionally stopping and frisking people.