If feel that with Youtube you get a touch of the Zeitgeist. There are some milquetoast channels like 'Hoovie's Garage', 'Rich Rebuilds', that tap into what average people are interested in watching.

You can also see the small changes in the medium; everybody at once adopting click-bait titles once one person was successful with it. As soon as a channel gets some success like 'Hand Tool Restoration' then everyone starts doing the same thing.