Maybe it is? In the old days, there were all kinds of restrictions on classes that invoked xp drain, tithes, economic vampirism, organizaion membership, duels, and item restrictions.
Maybe only fighters (and rogues I guess) can become kings and attract magic items by virtue of being free of all the background nonsense? Or at least be better kings and get better items?
These are questions we as a community must sit down and answer or the designers do it for us without our input.
Well, to stake a position. I don't like restricting people on social aspects via class. The idea that you are a famous fighter, and therefore people come to seek your knowledge and the king grants you land, but if you are a famous wizard people ignore you and you cannot hold land, is kind of silly to me.
If we are going to make land-ownership and followers part of the game, I feel like it should be fairly equally dolled out. With everyone gaining somewhat equal benefits from that sub-system
Additionally, differentiating the fighter via them being the one who brings ten extra people to the fight brings up issues of minionmancy and action economy that I really think the game is simply not built to handle well.
Since this is posted in the Level Up subforum, the vision of the high level fighter is that he can go toe to toe with the most powerful monsters in the Monster Manual.
That is, 99% of the discussion is wildly off topic for a game explicitly compatible with 5E.
This just isn't the game where you redefine what a Fighter is.
This is where you get to roughly the same power level as a level 20 Fighter, except you're given more interesting design choices along the way.
Then that seems like you are solely looking at expanding the battlemaster and adding a stance system. Maybe an intimidation aura.