Hi, yes - last year in NYC. AT&T didn't want to sell me a sim card - so I got a Verizon sim. They don't support all bands either, but it was less of a problem in the city itself. If you plan to stay there longer and need a working internet connection, I would take another phone. Unfortunately, none of the providers seem to work optimally with the Pocophone.

Yes, I can imagine. During my extended stay in California, my Honor 8 Pro only supported 2G. So because I needed a new phone, and after much online research from there, I saw that almost no China phones supported USA's frequency bands. Huawei/Honor, for once, when the disputes didn't exist, made an Honor View 10 compatible for USA. (But be sure to buy there, preferably Amazon, for the correct version). And it worked perfectly.
In the USA, there are pages where you can see which phones support which frequency bands from which provider. By the way, there is also a site like Comparis or something, where you can compare mobile phone subscriptions from all providers and sub-providers.