Early TikTok was basically a standard Chinese startup in terms of how they collected data to optimize the app... It's not because they cared about what "you" are doing.
The Chinese tech ecosystem is just more competitive than the US one.
Most social media companies have been careless with data until they got public backlash though... TikTok's systems are probably more secure today than anyone else's... Because of the backlash.
WeChat is an app that works inside China, so obviously it's subject to Chinese laws.
All countries have some restrictions on what is and is not okay to have on online platforms. China just adds in "social disruption" alongside content that could promote violence (which would be blocked on Facebook, etc. also)
You need to not just drink in propaganda... When something just "can't be done" (because it is being monitored), then it just doesn't matter even if you have ill intent.
Does that sound like a business or an intelligence front?
Although, they do seem willing to sell potentially.
China restricted them from selling their recommendation algorithm, and it's hard to sell TikTok without.
But, TikTok did immediately start work on an independent algorithm that has no ties to China, so that they can sell it if it really comes down to it.
And you are telling me this is perfectly normal.