right, but the stolen phones get sold in other countries where the carriers don't care if the phone was stolen but care that someone is spending money on their service.

I have never seen this happen.

I have however experienced that a ISP will write to you because you have a faulty modem (some Huawei device) and asks you to not use it anymore.

There is a surprising number of carriers in the world that don't care if you're using a stolen phone.

Not surprisingly, stolen phones tend to end up in those locations.