I've recently started wondering how many people are here because they're too toxic for regular social media rather than because they want to be here.

This has largely been my operating assumption as well since day one when I came over during the Reddit API lockdown. I was fairly active on a NSFW alt up until recently and I've actually seen dozens of comments from new users mentioning that the only reason they were here on Lemmy was because they were banned from Reddit and had no other viable options. They were always an asshole to the posters and the reality is that with a lower population of users is that there aren't enough other voices to drown out these people yet and you end up with a feedback loop of toxicity.