Earlier quoted context omitted.
Not sure if you know, but at least life in Sweden is pretty close to this. Contactless payments are everywhere (Apple/Samsung/Android pay) and the app “swish” works great for sending payments to people. Even some businesses have a swish QR code displayed in lieu of taking cash payments.
The brilliant thing about wechat (or alipay) is that they don't have a close affiliation to the banks. And therefore far less transaction fees.
It charges you 0.1% for withdrawal once you used up the initial 20K RMB quota, and the real profit driver is its own credit part, if the customer paid using credit from Alipay, which the company agressively promotes to users and urges to be set as default, the fees for businesses then adds another whopping 4%. Would they raise fees even higher? I think they want to. The duopoly raised fees in lockstep before.
It isn't that much different from other card organisations, except theoretically it encourages users to put cash on their platform's various funds and pay with credit it offers so it doesn't need to pay a clearance fee for every transaction. It takes away the protection for customers by credit cards, offers guarantee of receiving money without disputes to businesses.
So it really comes down to the time saving from processing cash vs the cost, since paying with bank cards or gift cards are uncommon in China, and usually you need to type your PIN as it's required by banks even for credit cards to avoid their fraud responsibilities. And the public inertia of not wanting to bring cash they are trying to build.