I personally use Lemmy for 2 things really, tech/foss/privacy news & discussion, and as a social media replacement (memes). When I used to be on the crappy socials, I would only really use them for memes, and left when I started to care more about privacy rights. The very first community I followed was 196 when they migrated away from reddit, so it was essentially what I came here for initially, and then found that the whole platform was miles better for discussion as well.