Carriers are for "power projection", not necessarily for warfare with nation-states.
The U.S. has treaty obligations requiring the ability to respond militarily to crises in Europe and Asia and so the requirement to be able to project power is basically enshrined in law. But most other countries want, at most, to be regional hegemons and so don't need a deep carrier capability.
So with that in mind it's still unclear what China plans to do exactly with their carrier. Presumably they will build some more, but they will never put it in combat against the USN (who have ample capability to destroy the carrier aircraft in the skies, and the carrier itself). But it's an awfully expensive fleet to maintain just to piss off Taiwan or Japan.