It is probably due to a number of people stopping using their alts after some instance hopping.
Also a few people who came to see how it was, and weren’t attracted enough to become regular visitors.
Curious to see at which number we’ll stabilize.
Next peak will probably happen after either major features release (e.g. exhaustive mod tools allowing reluctant communities to move from Reddit) or the next Reddit fuck up (e.g. removing old.reddit)
Stats on each server: https://lemmy.fediverse.observer/list
As I said in a comment below, I would like this to be a signal for interest groups to choose one of the dozens communities they have, stick to one and make it grow.
Looking at gaming or books, always seems detrimental to have the . world, .ml, .sh.itjust.works and so on with the same content posted everywhere.