Part of the trouble is that for most, those groups tend to be unstable. Maybe it's the fault of MMO design itself in 2022's social environment (especially with all the distinct roles that need to be filled to put together a group for battle content; there's probably a good reason why so many "modern" MMOs - especially the Korean offerings - dispense with the trinity in favor of a "everyone is DPS" system with simple individual dodge based mechanics)?
My observation is that large groups that actually stay steady in FFXIV tend to end up being almost exclusively serious raiders (who tend to function - more here than in any other MMO, at that - on a "strictly business" mindset, where personal friendship is even if anything considered a source of trouble).
Smaller groups almost always, even if you love them to death, devolve to the point where you can't even rely on enough people being around to do roulettes or weeklies, again being delivered to the mercy of the (increasingly long) DF queues. More often than not everyone even mostly gives up on FFXIV altogether and primarily plays solo or the currently trending MP titles ...
Either way, there tends to be a heavy disintegratory pressure towards the more mellow parts of the playerbase maintaining community, and the FC house situation is not helping
Right now I'm in a fairly large happy chill FC on my Maduin character, but also FC houses have not yet become available on Dynamis, so we'll see how things hold up once they do.