You're not wrong; I've noticed the same. Less 'horny' specifically, and more.... reasonable and engaged; vs impulsive and reactive.

I think the accessibility of reddit vs Lemmy plays a feature there. Lemmy requires at least some level of tech literacy to understand well enough to use, and it also isn't where most of the people are. So the people choosing to use Lemmy fully intend to use it; we're not casual users.

Because it's so easy to use, I think Reddit has a lot of young and/or immature people (demographics that overlap, but aren't the same). So it's full of impulsive, heavily-opinionated, casual users who aren't really invested in their communities, that can easily make a new account on a whim, and that create echo chambers with their votes.

It's not really Reddit's fault, tbh. It's an issue of user population, especially when 90% of the users do nothing more than upvote (so generically agreeable things rise) or downvote (anything that challenges them falls). The bigger a user platform gets, the more it homogenises.

Reddit was only unusual in that subreddits let it homogenise on a sub-by-sub basis and create echo chambers; a savvy redditor could still find smaller subs with better discussion (r/patientgamers rather than r/gaming for example). Or subs would get bigger and start becoming hostile or tribal, losing their original mission - and somebody from the old days would make a 'true' version (r/childfree vs r/truechildfree).

Lemmy is too small for groupthink to homogenise it (yet?). But particularly large instances could potentially go the same way given enough years. It's just that Lemmy being federated means that we can make new instances, and defederate from any that we may find unpleasant. I've already learned of one portal that isn't federated to my chosen one.