Here’s an article from an individual with a lot of experience over the decades with China.
The vast majority of Chinese imports that reach Western retail consumers to form this opinion are mass market products that were never meant to be of particularly high quality.
My experience with the state owned mills can be summarized in the basic lack of initiative to improve by most of the managers and technical staff. They had low pay and no incentive to improve and optimize processes ( continuous improvement), as I have been so familiar with here in US , so at some times quality would be OK and other simple cosmetic issues that could be fixed quickly in a motivated western mill would never be addressed. I met with a lot of good, knowledgeable, and capable professionals, but the lack of initiative could never sustain an effective continuous improvement program needed to produce consistent high quality materials.