I'm late to this reply, but Chinese pilots and aircraft have actually become quite competent this decade. Their behavior with international intercepts doesn't mean anything, especially when its usually done by some ye olde J-11s. And amazingly they kickstarted the LRAAM arms race again with their highly successful PL-15.

The F-35 does get to face off against China's J-20 and J-35, but to answer your question, the thing was built as an export product to make a ton of money for Lockheed.

While there is obvious technological advancement from the F-22, it has a top speed akin to a dated block I JF-17, reliability as good as a land rover, and parts/munitions expensive as golden caviar.

It's just an export all in one stealth solution because there is no alternative that was developed.

Which is why I want to see it pitted against any nation that has properly delved into counter stealth operations. I feel like if you can successfully light it up, it would struggle in a BVR fight, unlike the F-22 which has plenty of power to mess around.

There's no direct Chinese equivalent because both the J-20 and J-35 are more akin to the F-22 (although J-35 is a bit closer), but I would not be surprised to find the F-35 not being able to keep up with such adversaries.

And I'm fairly certain USAF is completely aware of this in their redteam exercises, which is why they continue to field the F-22 as their primary stealth air superiority fighter, if not outright their primary air superiority fighter.

Even more annoyingly for the USAF, I don't think the upcoming F-47 is going to come before China decides to jump on Taiwan, so they'll more than likely be fighting with whatever they have today.

The goal of the F-35 is to keep the lead in aircraft technology development. China can clone all the designs they want and build as many planes as they want but will need more then waves of planes to project power on the level of the United States.