Paper mills are bad but mostly from the perspective of academic institutions trying to verify people's credentials/resumes. Paper mills aren't really that much of a concern in the sense of published research results being false in the way the article is talking about because people aren't really reading the papers they publish. In that sense it doesn't really matter if there are places where non-scientists need to get one paper published to check some box to get a promotion, because nobody is really considering those papers part of established scientific knowledge.
On the other hand, scientists intentionally (by actually falsifying data) or unintentionally (as a result of statistical effects of what is researched and what is published) publishing bogus results in journals that are considered legitimate which aren't paper mills actually causes real harm as a result of people believing the bogus results, and unfortunately the pressures that cause that (publishing papers quickly, getting publishable results, etc.) exist everywhere, and definitely not just in China, nor did they originate in China.