Current breakdown at the time of this post sorted by the number of monthly active users:
- lemmy.world: 101,013 total users / 27,472 active users
- lemmy.ml: 41,972 total users / 4,905 active users
- beehaw.org: 12,270 total users / 4,178 active users
- sh.itjust.works: 17,509 total users / 3,381 active users
- feddit.de: 8,675 total users / 2,935 active users
- lemm.ee: 10,348 total users / 2,751 active users
- lemmynsfw.com: 22,967 total users / 2,310 active users
- lemmy.fmhy.ml: 8,777 total users / 1,704 active users
- lemmy.ca: 5,072 total users / 1,656 active users
- programming.dev: 5,058 total users / 1,242 active users
Sometimes it is, say here:
https://fedidb.org/current-events/threadiverse
But you might as well say why isn’t Mastodon included? Kbin is a fundamentally different platform and architecture, even if the two are largely compatible (as is Mastodon, to a slightly lesser extent with Lemmy).
It is perfectly reasonable to look at the growth of Lemmy, think of it like quoting use of one flavour of Linux - Linux uptake overall is also interesting, but not the same.
The Linux distro concept is a great analogy.