There are specific issues, mostly regarding clarity with regard to demonetization. It's all automated, and there are lots of errors.
H3H3, for example, made the video "Christian moms against dabbing" as a test for ad-friendly content, but was demonetized because of the word "Christian" in the title. It was not a controversial video, actually quite light-hearted, but the algo still triggered.
The frustration you hear/read is that many creators do understand the advertiser issues, but find nevertheless find it difficult to work with YouTube's automated systems.