How different is the tracking that TikTok does compared to what Facebook and Google does? Except may be TikTok might be shipping this data off to the Chinese?
It's not meaningfully different. It's not even different from literally every other successful business built on ads. They're all collecting data, and the ad industry is their customer - not the people making the content.
Exactly this is the point. It's one thing to allow companies in your own country/influence sphere (NATO/western world) to build massive data piles about your citizens, but an entirely different thing to allow a national enemy (or at the very least, competitor) such as China to do the same.
Given that there are many young soldiers, policemen, politicians or employees in security-critical environments it's not far fetched that a social media app such as tiktok which has cam/mic access is able to serve as a remote controlled bug for its owners. For what it's worth, ordinary tracking of location data is already an interesting data pile - a bunch of phones that for half a year only appear on a US military base and then suddenly appear somewhere remote in Afghanistan? Most likely they're deployed soldiers. Then look at what they post and suddenly you have names, ranks, specializations... and as said, all of that is possible with ordinary tracking, the dangers of an actual bug are magnitudes larger.