alt Hacker NewsAs of 2025 both AT&T and Verizon (plus, as a downstream their MVNOs) have a whitelist of allowed phone models and block connection of other phones even if they're compatible with the network.
See https://www.att.com/scmsassets/support/wireless/devices-work...
To be whitelisted, the phones need to go through onerous testing process that goes way beyond just checking for network compatibility.
I know there are phones that work on ATT that are not on that list.
Regardless, my point is that the situation has vastly changed over the past 20 years. It wasn't that long ago that you could walk into carrier's store in the US and literally every phone that was allowed on the network was on the shelf.