Facebook - Meme images about 2020/2021 and cute animals, with a lot of ads interspersed in between.  Photos of people making food, working out, or going to places.  Occasionally someone shares an article about mental health, politics, or social activism.

Twitter (via tweetdeck) - A lot of short jokes.  A bunch of pretty good art, sometimes really amazing art.  A lot of really cool creators posting insightful comments or just cool stuff.  Every once in a while someone tries to post what they call a "hot take" which ends up spurring on nothing but predictable responses.  Anytime something bad happens, all of the aforementioned things disappear and are replaced by doom.

YouTube - Lots and lots and lots of cooking videos.  A bunch of videos of people playing games.  Every once in a while some random chillhop mix.