

As I understand it they’re basically just avoiding doing anything that might destabilise the status quo. Changing the country’s name to something else is saying “we are actually a separate country from China” as opposed to being in a frozen war where both sides theoretically claim to be the same country. The ambiguity lets them be de facto independent and lets the PR of China say “it’s de jure ours” without either side actually going to war about it at the moment, so the ambiguity stays
You got a source for that millionaires per capita thing? China’s Gini coefficients are roughly on par with Western Europe