Just like everyone else: APIcalypse and enshittification of Reddit.
I think the real question is: Why a social news aggregation content rating forum instead of any other type of social media?
If I cared about people, I would be spending my time on Mastodon. Since I care more about specific topics, Iām here on Lemmy instead. IMO, the structure of conversations is also much nicer and more readable here on Lemmy.