e.g., you.com lets you pick preferred sources, so that you can tailor your search experience to your needs.
They've also done a great job on recipes. https://you.com/search?q=oven%20roasted%20broccoli
Neeva and Kagi also seem promising, though their both waitlist/invite only still
I don't work for them, but I have gone the paid route with them and I am very pleased with them as my default search now.
Google tried it in 2009, failed. Microsoft tried it in 2013, failed. Startups across the board have tried it.
I think it is because "social" usually implies to a user that they are searching for a person, not the content they create. And previously, there wasn't a ton of UGC that was relevant to a query.
Disclaimer: I'm a You.com employee working on search.
1. search something
2. click links until you get your info
3. go back to the search page and upvote/downvote the results based on which ones were useful