What these dorks don't understand is that "Han" is basically a floating signifier; it's more akin to a term like "European" or "westerner" than it is a specific ethnic group like Sicilian is.
The Han ethnicity is a melting pot or umbrella term for a really wide array of (sub)ethnicities that exist within it because ethnic groups were either dominant at the time and became part of the group or they were subsumed into it over the course of millennia.
I think this whole thing is just westerners universalising their own local experience and projecting it onto China - they aren't eradicating poverty they're just cooking the books, they don't trust their government because all (my) government is untrustworthy, they can't be making immense strides in infrastructure because ours is crumbling so everything they build must also be tofu dreg construction etc.
I'm not saying that there's no ethnic prejudice that exists in China - I'd be utterly floored if there wasn't any. But to make a tall claim like China being ethnosupremacist requires a lot of evidence and I'm not convinced that most Han people even identify closely with that label rather than their region or their particular subgroup so I think it's a real stretch.