The data stealing thing is such a cope too, I would rather a chinese company "steal my data", what are they gonna do with it? Increase my insurance premiums? Use it to call the cops on me? Share it with other corpos to raise my plane ticket prices? Yeah, thought so, they can't do diddly.
As for the child labour, it's a known social problem, and they're trying to solve it. Legally, child labour was abolished way back when, you can't work unless you're over 16, but of course that won't stop some people from sending their kids to work, especially in rural areas. As per this paper an estimated 7% of children between 10 and 15 were working in 2010 (yes, some 14 years ago). I can only imagine the situation got better. I trust to cite it because the study is done by Chinese people at a Chinese University.
I think there's a difference between a country where child labour is on the books illegal, people do it out of desperate social conditions, and the government are trying to find a solution for it, including supporting studies to get the real numbers; contrasted with a country where child labour laws are rolled back, were never that stringent to begin with, and are pushed because of increasingly desperate social conditions, as a trap to almost guarantee generational poverty from then on out.
edit: To be precise and to the point, the "child labour for TEMU" angle is demonstrably false. That sounds like people imagine that children are ushered into the iphone assembly abattoir, ooh, spooky. But this is all subsistence smallholders sending their kids to take the cows to graze after school, or pull out weeds and re-dig watering trenches. Or families that have otherwise not enough working heads and pressure their kids to take up work early. Remember, by Chinese standards, a 14-year old stocking shelves is child labour and therefore illegal.
I don't like TEMU, I think it's a bit crap, and I can say that without having to rely on weird sinophobia, it's that easy.