Latest study by Rent Cafe (if you want to believe them as a reliable source) says average apartment sizes have increased slightly in Manhattan. Rest of city things aren't so good.
https://www.nbcnewyork.com/news/loca...rough/4120686/
What continues to be true however is numbers are skewed by true luxury construction. In Manhattan you have eff tons of new luxury housing (and more is coming) where apartments are larger.
In an other interesting twist wealthy areas of city such as UES in Manhattan have actually lost total housing units. This is due to either apartments being combined to make larger units and or new construction replaces existing buildings but given total allowable FAR and lot size far less apartments are actually built. In short these buildings have less apartments but they are on average larger. Again this is all at true high end luxury housing.
https://www.thecity.nyc/housing/2021...in-past-decade