Reddit is heavily biased towards new content and you have to know what subreddits to look for to find the interesting stuff. The nice thing with Youtube recommendations (after recent updates) is that it pulls out a lot of older content and it also has a pretty good understanding of contexts and topics, even pretty niche stuff. Plain Google search really has no way of exploring the web in the same way you can just do with Youtube recommendations. Also helps that Youtube is extremely low on spam, you get ads and product placement, but not the bot generated filler that is cluttering up Google search.