Undrave
Legend
Lunging Maneuver. "Hit a guy over there, get extra damage". It's not hard.You need to keep the Champion maneuverless. There has to be a simple martial(Champion) and simple caster(Warlock) for those people who don't like or want complexity, and I've run into a number of them over the years.
The Champion actually has 2 decision points because it gets 2 fighting style on its way to level 20.Not simple enough. Even the "simple" totem Barbarian has 3 choices to make from among 3 options each time. 18 different combinations compared to the Champion's 0. It's not terribly complex, but I've played with a number of players who don't want to have to make decisions like that. They just want to write down what they get at a level and move on. The game is in their words, supposed to be relaxing fun, not involve work. D&D is an escape for them and they don't want to have to worry about character creation choices beyond race and class. The Berserker is often more maniacal and mindless in battle than players want. I've seen very few who have wanted to play one over the years due to the fluff and/or mechanics of it.
Plus, as I said, there is no good reason to change(or get rid of) the Champion. It's there for them, not you. You can pick from the other Fighter options or campaign for a new subclass that fits your needs.
And, I'm sorry, but 3 decision point isn't hard and the Totems give you basically passive buffs. The Bear is basically just 'be tougher', how is that in any way difficult or complicated? Heck, you don't even need to choose more than once and simply stick to the same totem all the way though. It's more complicated to order a sandwich at Subway for pete's sake and that thing will last you 30 minutes top, you pick a totem once, at the same time you pick the subclass by the way, and you're set for multiple game sessions.
If that's 'too complicated', present it to your player without the other totems as the Bear Totem Barbarian. Nobody ever picks the other ones anyway

Also, the Berzerker exist.
At some point we gotta ask ourselves how much more simplified we can make things for people who, frankly, don't seem to care about the game at all.