I am not new to 3P/FBA myself. I ran a store in my college days 2010-2012, and know number of Alibaba, and Amazon employees who were directly involved into managing vendors.
Among Chinese vendors, there is a very ambivalent attitude towards Amazon. People know that Amazon is at a times can be n-times more profitable than an analogous listing on Aliexpress, or any other smaller platform, but at the same time an extremely zealous enforcement is a giant turnoff to proper vendors.
Nobody who is ready to play "by the rules" goes to sell on Amazon among Chinese vendors because you can spend tens of thousands of bucks invested in the store for it be deletes without any questions asked.
Add to that that better vendors will not be bothering with creating shell companies, or using fake IDs to get Amazon verification. This way, Amazon has driven off the few proper vendors from China they had, and now they have to deal with fly-by-night, quick money types as they are the only ones who are ready to tolerate this treatment.