exactly me, I tried to get into Twitter a few times in the late 2000s and 2010s, but never could really see the use of it; nowadays I am a regular reader of Mastodon

Reddit meanwhile I have been active on (sometimes more, sometimes less, on different accounts) since 2014, so I can’t post a top-level answer here. I still enjoy forum-style communities like on Lemmy more than I enjoy microblogs, so post a lot more here than on Mastodon, but I read both regularly.