Even if China could build a reliable aircraft carrier, operating them is so complex, only the United States can do it.
Several other nations maintain aircraft carriers, and some of them are quite large.
The French and British can run air operations from a carrier, especially the French at this point. Both have at least one carrier of 70,000 tons. So it isn’t just the US that could field them.
The Italians and the Spanish both have active small carriers.
The Japanese have (I think) 3 to 5 “Helicopter Destroyers” which could in a matter of weeks be converted to launch and recover up to 35 STVOL aircraft each.
India has a carrier as big as the Chinese and is building two more. In fact, India has included carriers in their fleet for decades.
Brazil has a big old French carrier (Foch) but I do not know if it is operational.
Thailand has a small carrier but no planes and uses it as a royal yacht.
The Philippines have been making a bit of noise about buying a retired light carrier from Spain.