Quite a few apps run tests to find out if they're running on a rooted device, and refuse to continue if they are.
Dunno if these apps do that or not, but I can easily imagine that using them is a Hobson's Choice even in OSS utopia: take the horse offered (app with tracking) or don't have a horse.
To the extent you could ever replace WeChat and Alipay with OSS, that's already a possibility today even with closed OSes and App Stores.
To the extent that you can't (network effects or legal obligations or whatever) you still won't be able to if the code of those apps is made available under any license of your choice.
