I remember that in order to unlock the bootloader of my trusty old Xiaomi Mi 5 (I still use it to this day as a test device for development) I had to go to some website, say that I'm happy with unlocking it, agreeing to the terms and stuff and at the end be willing to wipe my device clean and have an "unlocked" written under my boot animation. I think these would stop your average joe, but now I've heared Xiaomi has blocked unlocking your bootloader in its entirety which is a shame, they used to allow root access from inside a stock app.