US cell carriers sunsetted 2G years ago. AT&T is sunsetting 3G no later than 2/22/2022. Verizon was supposed to sunset 12/31/2019, then pushed that back to 12/31/2020, and now it’s 12/31/2022. Verizon quit activating 3G devices on 6/30/2018. AT&T quit within the last year or maybe a little longer.
Yeah, my daughter got a notice from T-Mobile that as of 1-22-2022, her 6S will be inoperable on their network.