I'm gonna drop a bomb which is gonna make a lot of people I know upset.
GNU Social and all its derivatives are doomed to be dead end software.
GNU Social died a long time ago, and many times prior.
It swung left and right as its communities grew and died.
Its biggest selling point is the fact that it isn't Twitter.
GNU Social was never meant to replace anything other than proprietary networks in general.
Due to the overwhelming differences between it and Twitter, every time Twitter pozzed itself a little more, it'd have an influx of new users, who would then return to Twitter, and GNU Social would have a new death.
Eventually this cycle was broken by Mastodon. Mastodon, in the end, was worse than Twitter by far, but it exposed the nature of GS.
It simply overtook GS' cycles and has started cycling itself in the same way, expanding and contracting, rotting a little more every time.
Pleroma likely won't see popularity beyond the autists who linger in the Fediverse simply due to its non-left-wing nature preventing it from falling into the same cycle more or less.
In the end, don't bother with GS, Mastodon, or Pleroma. Use IRC or something that isn't prone to the deadly cycle.