The UN has released a report on human rights abuses in China, but has not called these a genocide. The more credible accusations of genocide came from a handful of political bodies in Western countries, but crucially the acting governments have not defined it as such.
There’s absolutely no consensus that the legal definition is met, in contrast with another ongoing situation which enjoys wide recognition.
It feels that this is more a geopolitical cudgel, pulled out when the discourse against the US becomes negative. But given the events in the last years, this seems like a lost cause even in the West, never-mind the rest of the world.