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?
Why are you comparing apples to glass bowls?
Lemmy is a reddit clone, where you create communities.
Mastodon is a Twitter clone, where you share what you ate last night or what political meme you like today while sharing photos of moss and/or windows.
Nostr is its own thing.
You can't really compare them with each other.
Yeah, I get your point. But the question still remains. Lemmy objectively has more engagement/interaction regardless of the category of social media of each medium.
If you compare X to Lemmy, X has more engagement/interaction... And they are separate social media platforms categorically. Yet, Mastodon trumps Lemmy's user count by nearly 10 fold...
It stands to question that with a fraction of the users on Lemmy, why is the interaction/engagement considerably higher?
Mastodon User Count Lemmy User Count
An average post on Mastodon/X/Bluesky/Threads is "this is what I encounter" or "this is what I believe". Those kinds of posts don't specifically ask for a response. You can respond to it, but it doesn't require one.
That's not how you communicate on Lemmy or Reddit.
That's the difference.
Each platform has its own usages.
So to compare and say "well platform Y is more social, because there's more interaction than on platform 2" is a bit weird.
You wouldn't compare a letter with a message board on a town plaza either. Both can be used to communicate, but they're not comparable to each other.
Or in another way:
On Mastodon or Nostr, when you post something only a small subsection of the userbase actually sees it (only those who follow you, those that follow any of the hashtags that you used, or those that check the full firehose).
On Lemmy the entire community you posted it to can see your post.
Obviously you can get more response on Lemmy! More people get to see it.
I think the answer is fairly clear. Lemmy's topics & votes system funnels condenses the user-base to focus on particular things at particular times. The total number of users may be smaller than Mastodon, but basically everyone on lemmy is looking at the top posts on the front page first, and then exploring to other stuff later; whereas on Mastodon everyone is just doing their own thing.
Focusing people on one topic means that there will be discussion at that topic at that time; and discussion leads to people checking back to read and reply to responses...
I routinely use both Mastodon and Lemmy. I see a lot more varied content on Mastodon, but it is more fleeting. i.e. very little discussion, and fairly short window of interaction with posts. Lemmy has a lot less 'stuff', but a lot more conversation.
I think the difference is interesting, but it definitely isn't something we should use to say which platform is doing better or anything like that.
Twitter have big interaction because user count is extremely high. For a microblogging platform maybe it requires that it needs lots of users and some "creators" who are followed by thousands of people, unlike communities which anyone can post and everyone joined the community can see.
I also think upvotes and downvotes plays a role too since mastodon does not have them(only boosts but boost actually shares with your own followers which might be very low)
mastodon is another "general interest" social media hub along the same vein of reddit or bluesky or .world or .ee, which means that (excluding its founding group) it takes many forms of long term investments to gain sufficient traction enough to establish a core group of active users (assuming that it ever succeeds at doing so at all) and that core group is a small fraction of its user base (presuming that a reddit post i saw years ago showing that a tiny fraction of users on social media are responsible for a vastly disproportionate amount of content on all platforms is true).
lemmy's political origins pre-included the identities and accompanying pre-built core groups that had already start coalescing in other social media platforms like reddit & tiktok. by the time of the reddit blackout protests those groups already had new online safe spaces in various lemmy instances and their ranks swelled at the same time other reddit users started to fill the ranks of other "general interest" instances like .world and later .ee
that link you posted on lemmy user counts reflects the "general interest" instance's difficulties of retaining a core group of active users that disproportionately create the most content. it's around this content is where you will find the interaction/engagement that characterizes lemmy's considerably higher engagement; instead of the news & link sharing lower interaction/engagement that characterizes the "general interest" instances.
right now; the "general interest" instances have a relatively handful of VERY prolific users expending a clearly excessive amount of time and effort at creating a sea of inactive communities & instances in the hopes that it might eventually serve as a basis for a "general interest" core group and i hope that they succeed; i think that the lemmyverse would be better with politically moderate points of view and i'm sure that the "general interest" instances won't lose all of their users to bluesky, threads, nostr, etc. by then.