they require them to understand the concept of what a 'server' is to even get started.
I've known 5 year olds start minecraft servers. And understand that each "world" is an "instance". But that's aside the point, as you're right that even Help-Desk IT people struggle to understand the difference between computer and server.
It's not hard, it's just new.
The "new" part is what gets people. All of this is new. Even the implementation of all of this "fediverse" is new. It will come with time! People probably didn't understand email vs snailmail, and probably had an even harder time with SMS/IM vs email when all of that came about just over 20-30 years ago. Most of these "complications" are from people that grew up knowing that the "internet" is basically 5 or 6 social media sites for very specific uses, and those 5 or 6 sites are older than most of the people using them, so that's all they know. Even for a dude in IT, the fediverse was a new concept to understand, and even difficult to understand how it could best be implemented for the masses.