The crucial difference is that China does it covertly, and partly through its satellites like N-Korea. Western support is open, and frankly the right thing to do in the face of aggressive invasion.
Eternal is a difficult term, but in Russia’s case they never cede anything except in the face of absolute catastrophe, like the soviet collapse was. For instance, Finland has not gotten any of the territories taken from it back, and will not unless Russia happens to dissolve into its states. And those areas are mostly turned into wasteland by now which will be the fate on Donbas too if they get it.
They’re prepared to do anything to get real user data for AI training. This little change gives them easily millions of files per day accidentally saved to cloud.