Right, but the US has been involved in combat nearly continually for the last twenty years, while building on the traditions and lessons that got the US to the position it's in. The PLA has never faced one, so all their doctrine and theory crafting is just that. Look at carrier operations, which Japan is going to have to relearn. Even with US help, it's going to take years to train all the people to do all the carrier ops and years more to build up the institutional knowledge to pass that on effectively.
It's like that with everything. China, doctrinally, prefers automatic grenade launchers over heavier machine guns, for the suppression role. But they have no real idea how that would work in real combat, because they've never done it in real combat. They've never had to supply a military force overseas, never mind across an ocean, and they haven't moved on Taiwan, which means they don't believe they can do so successfully, or they would have.
Meanwhile, the US once supplied the Brits, the Canadians, the Russians, while fighting a war on two fronts, across two oceans. Successfully.
The Chinese got wrecked against the Vietnamese, and they share a border. So their only real military experience is getting shit on by a country that's smaller than them and was at material disadvantage.
You'll pardon me if I'm not exactly impressed by the theory of Chinese military competence when the reality has historically been, shall we say, disappointing.