I stumbled upon [this video](https://youtu.be/SJh_Uir5EMI), which states that these mobile payment apps aren’t attached to banks in any way. This is in contrast to services in America which are generally tied to a credit/debit card or even directly to a bank account, such as Venmo and Google/Apple Pay.
Under the American systems, it’s obvious how money gets from the user to the service; the user gives it to a bank, and the service has authorization to charge the bank account when the user increases their balance with that service or purchases something through it. But without banks, how do the Chinese counterparts get the users’ money and pass it on to vendors?
I think your original video makes it a bit too easy. Both WeChat and Alipay work best when connected to a credit card, and then act as an intermediary like PayPal. That‘s not really a big difference, but probably the fees are much smaller because Alipay / WeChat work on both ends – for the customer and the receiving business, so less parties involved means less slices of profit overall.