At least we know one boundary - in London, about 91k phones were stolen in 2022, of which a lot are expected to end up shipped to China [1] to be either parted out or its identifiers reflashed so that they can be re-sold. The true number is likely to be significantly higher, as not everyone is willing to go to the police and deal with the paperwork when someone snatched their older-issue phone on the subway when the police doesn't do shit anyway.
And the latter part is the problem. The UK could impose inspections on outgoing parcels, say to listen for Find My BTLE beacons, and China could impose the same kind of inspections on incoming parcels or shut down the companies buying up clearly stolen property. But UK politics are too busy embroiling themselves in bullshit scandals and China most likely actively wants to contribute to the growing sense of destabilisation in Western societies, so here we are.
Assume an average value of 300 € per stolen phone, and alone London's citizens and visitors experience 30 million € in damage from stolen phones alone. It's utter madness.
[1] https://www.dailymail.co.uk/news/article-13757041/Chinese-ci...