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
I believe “active” sort has comments bump put an entire post, which has many threads inside it. Not sure if time factors into it. The “hot” algo is slightly more complicated that factors in votes and then time will heavily decrease it from appearing on the front page. Both algos punish smaller communities as they’re not going to be as active or have nearly as much votes.