As more and more instances are providing multiple services under the same management, we need a term to talk about this type of arrangement. A Fediverse Galaxy is a collection of federated software that is provided by the same admin or collective.
Top three #lemmy instances (lemmy.ml, lemmy.world, beehaw.org) are all basically the same size.
With #kbin 's kbin.social and fedia.io (run by infosec.exchange) in the same range.
I experienced it today looking for #NBA communities for the #nbaplayoffs , and it seems the biggest community right now (after literally 1day) is on lemmy.world not lemmy.ml
the threadiverse is a new colloquial name for Kbin, Lemmy, BrutaLinks, Prismo and any other fediverse software that implements a "link aggregator" type interface that has been popularized by the likes of SlashDot, Digg, Reddit, Hacker News, Lobsters etc