Your 2nd part leans towards the former.
Restaurant staff get their main pay from tips, they're paid below minimum (as two others here have also stated, one who thought he was contradicting me, no less), and off the books to boot.
Prices go up slightly as they always have, people haven't stopped going. Just another day in Da Big City.
As for millenials, the trust fund gentrifiers already love paying ridiculous prices for 'artisan' tacos topped with quinoa, goat cheese & mango chutney and Ramen soup made in places owned by people named Henderson from Ohio.
The real NYC millenials got their allowance or work for theirs and go for the real stuff at cheap prices, so no biggie.