Hardly anyone in NYC grocery shops every other week in normal circumstances.
Do you realize most people in NY have very limited storage space in their kitchens, no cars, and only buy what they can carry in 1-2 bags at a time because of that?
I have been in this situation too and yes it's not the convenient thing I'd do by default, but it is possible.
The cars thing I get, but most can carry quite a bit. Storage...you pile them, under the bed, corner etc etc. Whatever. We are living in horrible times
Of course you also need money to buy food for weeks, easy to say to others buy this and that)