Google is worse and worse for finding useful information and I think that community curation can be a better way to find knowledge.
actually here's an article i like on that topic https://future.a16z.com/the-future-of-search-is-boutique/
I'd say you don't need ranking in the sense that it is done in Google now. You need to able to make clusters of information based on searches and let people dig in.
like "react keynotes" or "routing in react".
Community curation is a good concept. I'm a little hesitant because community contributions can degrade a platform (e.g. people writing marketing content on Wikipedia). But the biggest hurdle had been building a reasonable content index, so despite that risk, the reward will seem to be worth it.
Re ranking: what you're saying makes a lot of sense in the context of topic discovery. But is less useful for q/a or reference style searches. Although it will still probably be good enough.