I think those Youtubers did bring in a lot of people, but only a hardcore bunch have stuck with us through the ups and downs.
Communities are a bit of a mess. Perhaps peakd could suggest communities to look at based on the tags you use. There could be more intelligent use of tags as a lot of them are pretty pointless.
I also don't like those 'curation' communities. Nobody is going to go looking for content to actually read/watch/listen there. There is too much emphasis on strategic voting and not enough on real engagement.