You will be shocked how many paraphrasing enthusiasts will not finish their implementations, if the first steps require additional expertise / investment.

Google should definitely resolve this problem on their side, but language models got huge and complex. It's hard to tell (especially with their scale) if a website if composed from paraphrased content of 20 other websites.

I'm kinda shocked how successful those "doorway pages" are at reaching the top and how long they live there.