Google knows how to surface relevant results and they choose not to because they aren't optimizing for relevant results, they're optimizing for revenue or profit within some constraints (don't lose too many users, privacy, avoid actually terrible or completely irrelevant results).
All the various suggestions in this thread plus far more complex and insightful solutions are known to Google. Most of it boils down to using automated user feedback to improve or measure search result relevancy.
Google doesn't need to solicit user upvotes / downvotes to improve rankings. They can monitor user clicks on results in addition to analytics on the sites the users visit to determine which sites are relevant to which searches.
Likewise Youtube doesn't optimize for relevant results, only engagement to maximize ad exposure. The side effect of this is polarizing content gets returned more than relevant content (polarizing content being more engaging than relevant content apparently).
All the various suggestions in this thread plus far more complex and insightful solutions are known to Google. Most of it boils down to using automated user feedback to improve or measure search result relevancy.
Google doesn't need to solicit user upvotes / downvotes to improve rankings. They can monitor user clicks on results in addition to analytics on the sites the users visit to determine which sites are relevant to which searches.
Google doesn't optimize for search relevancy.