Brace yourself for a weird recommendation:
Don’t worry about it or switch to ios.
You’re on a different marketplace for phone apps than chinese nationals so you’re not getting the same wechat as they are. If you trust your platforms marketplace and your phones security and privacy tools then just don’t worry about it and use them like a normal person.
If you don’t trust your platforms marketplace or security and privacy tools, switch platforms.
It doesn’t seem from your responses in this thread that you’re in a good spot right now to learn everything required to root and run an alternative os securely and act as your own security auditor. Not a value judgement, I’m not in a position to act as my own diesel mechanic. That’s why I said maybe switch to ios if you feel exposed by stock android instead of saying you ought to try to navigate the alternate os/custom rom world.
It might seem like some people in the replies have given good walkthroughs, and they definitely have, but at some point you’re gonna have to make a decision about something that either isn’t documented on a wiki or no one responds to questions about.
Maybe the best choice is to either not worry about it or switch platforms and no matter what you choose, put the phones security and privacy tools to use and be more considered and self aware about how you use your phone.
E: Jesus Christ. Some of the responses you’ve gotten are astonishing. Maybe ask in hexbear or something just to get an alternative view.