>As if the only option is to give objects back to poor or corrupt governments. Even if true that doesn’t mean people are undeserving of their past. How about strengthening local non-governmental institutions to care for these objects?

Right, and if that doesn't work, or until that works, is it morally objectionable to hold on to those objects? Is it truly the right thing to return items to governments that can't guarantee their safety or don't hold those items to the same values? What's the better choice here? Preserving anthropological history of mankind or respecting the wishes of hereditary descendants? What if they don't give a shit about their past? Does the rest of the world need to be deprived of the history of humanity because the current, local, inhabitants don't care for their own? Your solution is to teach them to care, which is hilariously just as colonialist and culturally "appropriatiative" as the person you're replying to.