My son's Xiaomi Pocophone F1 is probably the best value smartphone I've ever bought.
Absolutely no disagreement from me. Xiaomi products are sold at cost or less, they are the some the best value devices around.
The process of unlocking the bootloader however requires - mobile data connection not wifi, use of a proprietary unlock program, a 360 hour (15 day) cool down period in which if you dont use the phone for normal tasks more time is added, registration with email and phone number and a sinister string in the unlock program: "Unlock failed, too few or too dark portraits".
Xiaomi started with people making the MIUI custom roms... their production of smart phones is a vehicle to get MIUI into peoples pockets.