Hussar
Legend
I'm not phrasing it well.I mean I agree Barbarians are a smidge more complex than fighters. More on/off toggles to remember. But they aren't really complicated either.
It's not that barbarians are particularly more complex than fighters. But they are a lot more fiddly. Like I say, constantly having to divide your damage, and remembering which damage types apply, plus remembering that you damage changes if you are raging or not, plus remembering to reckless attack and then remembering if you have reckless attacked, and that sort of thing.
There's a lot of fiddly bits in playing a barbarian that don't exist in a fighter - certainly not a champion fighter anyway. I know watching the current player in my game play a barbarian and constantly having to remember all the bits - plus his subclass allows him to do extra fire damage on a hit (I forget the name of the subclass - Path of hte Giant? something like that - which changes his size when he rages), which is just incredibly fiddly.