Interesting article in The Real Deal:
https://therealdeal.com/2019/10/09/m...entee-tenants/
Rent stabilized apartments are required to be one's primary residence. However, the system is abused by tenants using these apartments as pied-à-terres or subletting them for a profit.
The primary enforcement was for landlords to take these tenants to civil court and get them evicted, but now there is no incentive to do so (due to the 20% vacancy bonus being eliminated, rent increases for improvements being much more limited, and near impossibility of deregulating the apartment).
In fact the landlord might actually prefer having an absentee tenant under the new system due to less wear and tear on the apartment and the possibility of the laws changing in the future to crack down on this type of fraud. I bet there will be a steady increase in the number of absentee tenants over the next few years.