However the very fact that we can discuss these things (or that there is a book that is freely accessible to all on the subject of a specific instance of institutional oppression in the U.S.) openly and without fear that our doors are going to get knocked in and see us getting swept off to a "reeducation camp" are the signs that we live in a country that strongly values free speech.
The U.S. does not have a perfect track record by any means...but for all of the examples you give of bad action by the U.S. as an institution I am aware of large and public and accessible documentation in the forms of museums, installations and other means of dissemination and availability.
In other words the U.S. airs (or allows to be aired) its dirty laundry as much or more than most other countries. And while this invites "whataboutism" it certainly, in my opinion, helps validate our position to openly question and try to discuss the actions of other nations.
https://www.zinnedproject.org/materials/assassination-of-fre...
That said, what is being done to the Uyghur people in China is vile and is contradictory to established human rights. It is completely appropriate to take China to task at the UN. However, as US citizens, it is difficult for us to have a strong moral voice given the wars, assassinations, coups, and destructive sanctions we have initiated along with our history of indigenous genocide, colonialism, and slavery that we have still not fully reckoned with. Even now we are implementing a slightly different version of the Japanese internment camps for the most vulnerable people in our society, undocumented immigrants, to distract from the economic depredations of the ruling class.
If we want to be a more effective and just nation, we have a lot of work to do at home.