I'm not being snarky asking this. I'm legitimately curious. In your opinion, how many of the publications were real scientific advancements and how many were bogus political screed writings masquerading as "science"?
Well there is little in the way of “bogus political screed writings” but there are big problems that permeate scientific publications. Not just those from China but from everywhere.
First is repeating what should be common knowledge in a particular field (I do materials science and packaging). We don’t need to know everything about, say a polymer, in the introduction. That’s what encyclopedias are for.
Second is that all sorts of strange and unuseful materials are fabricated and written about. Many of them read as if some student needed a Master’s degree thesis topic so the professor went to the chemical cabinet, pulled out a bunch of random reagents and said to combine these into a novel product.
Often you have to wade through papers until you finally find one in which the researchers did something that is actually useful.
Third is repeatability. About a third of the experiments from publications I have repeated for product development turn out not to work.
If you work in private industry as I do you need to consider simplicity, cost and usefulness to the end user. For academics the publication is the goal, not a product.
The Chinese academics have these problems just as much as do their international counterparts. But hey, it’s not their money they’re playing with, it’s the taxpayers’.