Adding friends, shopping, logging in on PC, binding accounts for after-the-fact SSO, etc..

This is all done with QR codes here.

Thankfully I don't live in China. Unfortunately the totalitarian government is a larger concern than the QR codes.

They don't like contactless technology or what? I don't think that scanning a QR code is significantly more involved but it's enough to be annoying

Also in adjacent countries like Vietnam etc., where even ragtag street food vendors have a QR code sticker on their stall/cart.

It's so common that people pay without even talking or confirming; I've seen customers just take their phone out, point at the QR, and walk away, and the shopkeeper says nothing. I'm assuming the shopkeeper gets a notification on their phone and trusts regular customers,

but how easy would it be to secretly place your own bank account's QR code on top of a shop's QR? People who wait for a confirmation notification will catch it immediately, but by then the customer has already paid the attacker and the transaction can't be just reversed. Repeat it in several places, and a thief to snatch quite a few payments before the parasite stickers are all taken down.