I think it’s a flex. And not just for ego/pride reasons.

They’re showing the world and the world public that their military technology is not only on-par with the U.S. improving rapidly, but also starting to surpass it. Public opinion does matter in that regard because a state’s ability to wage war hinges on public war support. This is also why Western media is working so hard to poo-poo this development.

And of course carriers are superfluous to China’s current military doctrine but strategic agility and flexibility is a luxury they can afford now, and given the volatility of current circumstances it’s arguably a necessity, not a luxury.

One of the main advantages of a multipolar world is that the powers deter one another from intervention, which allows places like South America to have their leftist movements without getting couped or invaded. China needs to be able to project power eventually as they step into that role.