That still isn't a concept. At all. The rogue is also that, but also other things. Most fighter subclasses are that, but also have an identity.
Sure, the archetypal hero is a concept. It just subsumes redundant concepts like rogue, ranger and the like, but D&D deigns to give them classes, anyway. ;P
The fighter was popular in previous editions because it was simple and it was the only class that could be excellent at weapon use. In modern dnd its part tradition, part "here is the most basic, simple, learn to play class"
I really don't think so. In 3e, for instance, the fighter was /not/ the simplest class and the only one that could be good with weapons - the Barbarian was simpler and very effective at swinging weapons around, and it was the ideal "training wheels" class because it had mountains of hps and rage taught you to manage resources - /but the fighter was the most popular class/. In 4e, almost any striker played simpler than a defender - an Archery Ranger was the simplest thing you could play - but the Fighter was the most popular class.
Obviously in 4e, just the addition of a role adds an actual concept to the fighter. They're a protector, a frontline tough guy who keeps enemies away from their allies. It's a thin concept, but at least it's mechanically interesting and very effective.
It was always there, though: the fighter's job was to stand in the front, preferably two of 'em in a 10' corridor, forming a 'wall' to protect the valuable characters. In porting that to primitive AIs, game designers came up with Aggro, and then sometime in the 3e era, people started noting that the fighter /didn't have that/, even though the way the fighter had always been was /why/ it was invented. ::sigh::
But in 5e, there isn't really anything there.
Consequence of being designed (unnecessarily) for "simplicity," I guess. That and stretched thin covering the basic bone-simple old-school pre-everything-cool fighter, the 4e Weaponmaster (and it's 6 or so builds and 400 powers) and Warlord (and it's 6 or so builds and 300 powers) and 3e & Essentials Knight and 3e featastic customizeable fighter (and it's 11 bonus feats) and 2e DPR-king fighter, /and/ old-school Fighter/Magic-User, all in only 3 subclasses and two bonus feats.
Yeah, y'might have a point there.
IMO the rogue is a better fit for the archetype you're talking about. The fighter is that guy's sidekick who is there to comment on the hero's actions and troubles and thus inform the listener/reader/audience.
... OK... I can think of an example or two...
either way, actually. Tough hero with sneaky side-kick or vice-versa.