This means Google would be determining whether Taiwan is an independent country or not, making either China, or more probably Taiwan unhappy. Something besides the browser would need to determine what your list of countries is, like the site itself... but a solution like that is much less elegant. Chrome having regional behavior also just sounds like more mess for devs. Some sites will deliberately want to pick sides, and should be able to.
Geographic data will have to come from somewhere, to add countries to this list that "don't exist" in whatever the built-in list of country options is.