Shardstone
Hero
If the subclasses for Barbarian were more mechanically interesting and featured more choice, and if the subclasses for the Fighter had the same flexibility as the Rune Warrior and Battlemaster, this just wouldn't be a problem at all in my opinion.
The only thing missing is agency outside of combat. If Barbarians and Fighters had options in their subclasses that gave them more magic access, be that in spells or raw abilities, or that let them make things happen, such as maybe the Totem Barbarian can invoke the strength of the bear to lift a Gargantuan object or something, then the divide shrinks.
But, all the shenanigan options are locked behind spells and exclusive subclasses. This is because high level D&D just isn't well designed IMO for pure martials. While caster's get to cast Earthquake, the Battlemaster Fighter gets to start combat with 1 superority die if they don't have any. Yes, its a mechanically significant feature for power, but it isn't nearly as fun or interesting to use.
The only thing missing is agency outside of combat. If Barbarians and Fighters had options in their subclasses that gave them more magic access, be that in spells or raw abilities, or that let them make things happen, such as maybe the Totem Barbarian can invoke the strength of the bear to lift a Gargantuan object or something, then the divide shrinks.
But, all the shenanigan options are locked behind spells and exclusive subclasses. This is because high level D&D just isn't well designed IMO for pure martials. While caster's get to cast Earthquake, the Battlemaster Fighter gets to start combat with 1 superority die if they don't have any. Yes, its a mechanically significant feature for power, but it isn't nearly as fun or interesting to use.