I didn't like that at one point, google added a qr code scanner to my android lock screen. Especially with no easy option to disable it. Why is there no option to disable it? My mind went straight to "it's a backdoor". Like if it scan a specific QR code, phone unlock. Disabling the scanner involved disabling a system app.

Know I'm thinking the same about the mandatory pin unlock. What if there was a universal pin? I cannot disable that pin keyboard.