Contrary to many posts here, I think that Google completely controls the quality of the results. The feeling is that quality has gone down because a lot of top ranked website are SEO ads filled websites. I think this is true and on purpose. Two years ago top results were very often Wikipedia, Stack overflow or reddit. Sending users to those websites is not profitable for Google. I also think that's why it's very hard…
I don't quite understand what you mean when you say "sending users to those websites is not profitable for google" - referring to Wikipedia, Stack, Reddit etc... Organic search results only ever profit Google if they answer the user's question, because it makes that user more likely to use Google again and click an ad in the future. If a user searches something and the top result doesn't answer their question, then G…
Obviously the best for Google would be to send the user to a website with the best content and that contains Google ads but that's often not both the case.
It's an optimization problem, and generally you cannot optimize for two variables, profits and user satisfaction.
Maximizing only for profits would probably lead to completely garbage results so they probably have to compromise.