Maybe we should step away from China for a moment given their government has a very strong motivation to keep tabs on its citizens and the fact their very mention is biasing the conversation and look at another country which has a strong smartphone presence and I often see posted on here as an example of privacy - Norway
We’re effectively cashless (I don’t think I’ve even handled cash since they swapped the banknotes over) and I think most people do their banking from bills to petty transfers on their phone. You can’t get a physical bus card, because that’s on your phone, or the ticket is attached to your bank card. We don’t have an all encompassing WeChat or even like, any homegrown social media. I’m not exactly sure which aspect of WeChat you’re honing in on so I can’t say Norway does that too, but we do an awful lot via our phones. I do have some gripes about how some things are set up, but they’re complaints that aren’t actually exclusive to this specific system.