Google engineers can't even filter out GH or SO scraped sites like gitmemory, nor offer a way to let users block these sites. I'm not sure we should expect them to handle more advanced techniques like detecting word swaps any time soon.
The other reason is I started using a search engine that cracked the code to let users rank and block sites (kagi) so I don't have to worry about it.
The reason those results remain in your searches is because sending people to those sites makes Google money, and by definition that is of greater value to Google than the quality and relevance of your search results as a non-paying user.