WeChat is just how things are paid for here, obviously the solution would not rely on WeChat in any other country. In Australia you'd just tap your credit card.

Of course it is easy. You can just pay with a credit card or mobile payment etc. like is already done when paying for parking. Even easier, the charging around where I live you have an account and a card and you just swipe and charge and the bank transfers the money monthly. Solved many years ago. The only thing that isn't all the way solved is the massive drain charging lots of cars at the same time can induce.