I see what you're saying but do we need a literal faceroll character? I like the idea of simpler and more complex character options, does barb have to be even more straightforward to qualify?
In any case, my feeling is the "complexity" of barb, such as it is, comes back to their janky character design. Decisions for a barb revolve around some rather gross deficiencies, like being essentially useless if they not raging (and rage only activating on their turn AND being annoyingly easy to drop). If barb didn't live and die by rage, they'd have less glaring weaknesses and thus the player wouldn't have to sweat every use of rage or reckless attack in the same way.
Totally agree; an easy way to vastly improve barb would be to give them extra ASI's. They are feat AND attribute starved relative to fighter and even paladin.
It's not a rule, it's about what they bring to the party. Can they cast bless? Can they cast healing word? Can they cast silvery barbs? What about faerie fire? Can they use runic shield? Ancestral guardians? Aura of protection? Thunder gauntlets? Twilight Sanctuary? Balm of Peace? Web? Darkness? Plant Growth? Hold person? Bardic inspiration? Flash of insight? Can they run up to a pack of enemies and just soak hits for the team? Etc etc etc
Do they act as a force multiplier, or are they just kinda doing their thing? That's what I mean by selfish.
Not to say they have NO abilities like this, but not very many, and not very good ones.
EDIT: arcane trickster gets some of the spell goodies, so I'll admit that what I said doesn't apply to that particular subclass very well. But, ranger isn't a good class just because gloom stalker exists. Rogue isn't a good class just because arcane trickster exists.