Because NO ONE else seems to be up to the task.

I think folks here are getting lost in the weeds about precise definitions which don't really matter that much and what they think are laws that can be applied across national boundaries (generally, that's not feasible).

There has been an effort to ban "conflict minerals" from modern supply chains. It's partially successful (in that you effectively get "a sticker" that you can show-off if your supply chain doesn't use children as miners). It would be nice if, AT LEAST, a similar half-measure could be done for "forced labor" (or whatever you want to call what they're doing to the Uighurs).

Because without consumer, there would be no incentive for either China and Apple to behave amorally.

China is a totalitarian dictatorship. As long as it's citizens don't rebel, they have no incentive to change their behavior. Apple is a publicly traded company. They need good publicity.

So, as a humanist, I say it's up to the consumers to force Apple to stop contributing to human rights abuses.