SIM/operator locks have been already rare (in Europe) for a while, and that's great!
But there are Android phones that come with bootloader/OS lock, which often means old device is stuck with some ancient OS version (and some bundled bloatware), instead of being able to be reflashed to a recent LineageOS.
The new phone lock du jour is the manufacturer's anti theft mechanism.
I recently got two iphones from their owners, pulled out of the drawer to monetize them on classifieds. Both locked and unresettable without the previous owners help (one could be unlocked because I got her account password over the phone, huge nogo but she trusts me to not screw with her account). The other not, account was lost.
Apple also now tags and ties both battery and camera to the logicboard. Shame.
This one is a pretty obvious trade off, does anyone know of good data on the impact of Apples policy on iphone theft rates and/or sales rate of stolen phones?
But there are Android phones that come with bootloader/OS lock, which often means old device is stuck with some ancient OS version (and some bundled bloatware), instead of being able to be reflashed to a recent LineageOS.