FCs are incredibly hard to run and maintain. Everyone wants something different. Creating and maintaining events is difficult as people have a tendency to not show up, not take it seriously, cause drama or something of that sort. And herding cats is just not for everyone.

If you have a few people who are dedicated and are willing to cooperate and work together an FC can grow large. But that isn't the easiest thing to do either. I was in a good sized FC and the leader finally kicked everyone and now just uses the FC for him and his rl friends. He had weekly events, constant buffs, website, voice chat, perks like free gear 1-15, old content runs, etc but no one would help him, people wouldn't show for events, some joined just to get thru coil or the ex primals and drop. Heck we couldn't even get 2 other ppl to come to the FC house to help with workshop crafting when 15+ were online. He spent all his time recruiting and leading events to the point he couldn't enjoy the game himself.

So FC management isn't for all. If you have at least 3 people running things, sure you can get huge. But that's fairly hard to get, from what I have experienced since arr launch.