Having tried all three, its a stark difference in how much more social Lemmy is comparatively. Its not even close. Almost all posts I've encountered on lemmy have interaction; whereas, more often than not, posts on the other two platforms have no interaction. Wonder what the driving factor is behind this difference?
I've never heard of Nostr but Mastodon is a twitter clone and I don't find that style of website suits discussion well since you subscribe to accounts rather than communities.
I've never understood what twitter style websites are actually for. They seem to have a tiny niche of celebrities and known personalities making a statement with no reasonable conversation stemming from it.
I don't understand how that structure was once one of the largest social media platforms in the first place.
In my experience Twitter was for modern Seinfeld jokes, mastodon is for monsterdon Sundays at 9pm et, and Lemmy is for commenting on Internet stuff.