I can absolutely understand that it's difficult to conceptualise. For someone who already understands, the concept is dead simple.

But I still remember the confusion trying to join Mastodon all those years ago. You are shown a list of servers, huh? Never being introduced to the concept of federated social media, just being asked makes you feel like you don't belong because you don't understand what's happening.

Ok, so you search around and work out that it's across many servers. You now have to somehow pick a server with no frame of reference. Pick randomly and hope you don't pick the lemmdgrad equivalent (which is always high on the list on join-lemmy.com BTW). Then you go to join and you have to apply - oh, but what if they don't want me? How do they know who I am, why would they approve my application?

Each one of these things is a barrier to entry, they stack like swiss cheese so that very few people make it through.

Then there's the part where all these people have friends that could help them through it, but the friends never mention the fediverse to them because of the whole don't talk about thing. I am guilty of this.