Xiaomi have required this for a while now, not sure exactly when but at least since 2016. The other big Chinese brands that have cheaper high end handsets don'

Xiaomi have required this for a while now, not sure exactly when but at least since 2016. The other big Chinese brands that have cheaper high end handsets don't offically support unlocked bootloaders as far as i know. They subsidize their handsets with all the junk that their custom Android UIs push, so don't want owners to flash a custom ROM. The top 3 phones in the LineageOS install stats page are Xiaomi for this reason. https://stats.lineageos.org/ https://stats.lineageos.org/ Often phones that do support unlocking (without the hoop jumping) you have to pay a premium for, like the Pixel.