Because the general idea of conservatism doesn’t exist in either of these countries? Try again.
There are only specific cultural understandings, each of which almost always map poorly when applied cross culturally.
That’s just untrue and shows a misunderstanding of what conservatism is, which is about small gov and a return to the roots of said gov. While individual beliefs of how this should be achieved will very between the different nations, the general concept is the same.
From the little I understand, it's complex and dynamic and opaque to the point that current scholars and US government entities studying China have difficulty explaining it; I'm not even going to try.