> i have no reason to believe they're being truthful on this one particular thing
The problem is that your claim is unfalsifiable. Any evidence that I present, you'll claim is wrong, because it opposes your view. There are independent groups that went to China to investigate--you'll claim they're just CIA-funded. There are groups from inside China that have investigated this--you'll claim they're also CIA-funded. And the "evidence" that you present to back your claim is that they must be CIA-funded, see what it is they're supporting!
I'm not claiming that the media tells the truth. What I'm claiming is that your position is not based on evidence.
Unfortunately, no. There are evil things that happen all over the world, and the world powers are powerless to fix it. If <insert world power here> mobilizes its military to topple a government doing evil things--now what? People will be (rightfully) mad that the world power literally installed a new government, so the government will be unstable and illegitimate--and this will likely only cause even more strife.
I mean, not "all the evidence." For one thing, China doesn't deny that the camps exist--they just claim that they're for "reeducation" or "work training." For another, other people have reported on the issue, and shown that the camps are real.
Unfortunately, while I can present sources to rebut you, your claim isn't falsifiable, since you'll just assert that any source that I present is "US counter-intelligence / the thinktank blob," because it rebuts your claim.