If Reddit had a soul/conscience, I think it was us, and we're all on Lemmy now...
As a little background, I didn't actively use Reddit for months following the blackout. I still barely stop in over there and if I do I'm never logged in our contributing to the communities there (where I was previously a daily poster/commenter).
Just bringing up a point that I'm not sure I'd seen anyone discussing directly over here; the general sentiment and quality of posted information on Reddit has become tangibly worse in multiple ways (I think coinciding with this group, us, leaving).
Now don't get me wrong, Reddit sucked in many ways and for long before the migrations to Lemmy, but there is a noticeable difference in a few key areas:
Less skepticism in replies
Less sourcing of information in posts and replies
Less counter positions expressed generally
If there is a decent reply, you have to scroll much further down to find it
Less plain labeling of obvious bullshit
Many of us used to introduce counter viewpoints or clarifying information into posts, with sources. That functionally worked as a roadblock to stall the quickly building momentum of disinformation/misinformation. Those roadblocks often feel absent over there now, IMO.
Not saying we hold a responsibility to go back there or that we were saving lives before, but the difference is very apparent to me - Have you seen it? Any examples?
That number doesn't really tell us anything about the amount of post/content generation that was lost. One or two persons could change the general tone of a smaller sub easily, and often did so.
If only those two hypothetical posters left it could very well lead to a downward spiral into whatever bullshit is going on over there now.
Some of the smaller more specialised subs I frequented simply don't exist anymore due to what happened.
If you had a grain of rice that tasted unimaginably, unmitigably, good. The highest quality grain of rice ever seen in the world, in all of history.
It will not change the flavor of 30k bowls of rice.
We're talking an absolutely tiny amount of users here. And we shouldn't delude ourselves over it, circle jerking for being the "higher society". Reddit didn't change because we left, the number of users on Reddit change more on a daily basis than 5 Lemmy's.
That said, the smaller niche subs definitely saw some hits. I won't deny that. However, by definition, a small number of users leaving from small subs isn't a "gotcha" moment for what I've stated. That's is, almost by definition, what would be expected.
The discussions here are of higher quality for sure. But you'll still notice that in many threads it's almost indistinguishable from Reddit in many ways.
I generally agree with your point, that said, in the analogy you gave, the flavor would come from the posts, not the users. We don't know what the breakdown is between "active users" who create more posts and comments and those who are more like active readers.