That's because China suffers from what the West and East Asia does: overeducation. Most jobs don't need a degree. Another issue is that Chinese youth have been told that if they get a degree then they "deserve" a better job, so I suspect part of this unemployment is just them turning their noses up to "unworthy" jobs.Of course not, but there already is a steady increase in youth unemployment over the years as more youngsters graduate from college but find out that there is a mismatch of supply and demand of many occupations.
But this is the same problem as in Europe where you have people with university degrees working as baristas. There's simply too many graduates, which means that the quality of the average university-educated person is much lower in 2023 than it was during 1960 when only the top 10% of the population went to uni.
China is unfortunately repeating the exact same mistakes as everyone else. South Korea has had very low fertility for many years, but part of it is due to overcredentialism, which postpones childbirth. China seems to be going in the same direction.
I think the German model is better. Focus more on vocational schools for most people and universities should just be for the top 20% or so. But this is politically very difficult to achieve, as parents want to think their kid can and should go to university when in most cases the answer is, not really. So even in Germany, this model is weakening. Very hard to solve.