It’s been a while coming. They had a disaster in Tokyo, missed out on bronze in 2019, tried their best to give it away in 2018 and finished 3rd in Rio because of Mao Yi’s meltdown when they were actually quite a bit better than Russia on paper. There’s a definite trend here.
Why it’s happening is a more complicated question. I mean, they are actually still pretty good! It obviously is a risk to stack your team so much on your strong events and basically ignore vault, but it’s still a tactic that could get them a medal if they were capable of hitting.