Chinese people are extremely anxious—so anxious that employment for those aged 30+ is discriminated against:

Actually, by modern human standards, the prefrontal cortex is fully developed before age 30—only then are you a true adult in the real sense;
many people “politically awaken,” “gain philosophical insight,” and “wake up” at around 30,
which happens to line up with the stage when the prefrontal cortex is developing.

Age 30 is actually the right time to do a lot of things.

The reason Chinese people discriminate against those aged 30 is that the overall social environment is squeezing people:
excessive overtime, excessive depletion of the body.

In fact, although the physical strength of those 30+ has declined somewhat,
it is still not the case that they’re “unable to perform the job”;
when companies discriminate against people over 35 and relentlessly squeeze out younger workers under 30,
it all means they’re using an immature prefrontal cortex to panic blindly and mess around blindly:
crude governance, lazy administration, waste, and decision-making that’s not scientifically rational.