Thats been the trap of the past. Fighters are always given more and more combat things. I mean, many of the suggestions in this thread are about combat and not exploration or social pillars. The issue is that everyone engages in combat so when cool things are added, folks want ways to get them for every character. Which, is why I think the fighter could use some unique non-combat stuff of their own.
I really appreciate the deep dive approach you're taking. Rather than suggest precise solutions – I've contributed to, and started, plenty of those threads – I'm going to try to keep this poetic and focus on concepts...
"The ranger watches over the hinterland and the paladin crusades for the temple, but the fighter
safeguards the hearth. Kith and kin, hand in hand with hard-wrought will, these things in equal measure do a fighter make. The fighter may die today, but tomorrow a sister or cousin, child or nephew will pick up the fallen blade. This
legacy endures for the hearth fire must endure."
"Fortune there may be, but that is not why we fight. Vengeance, justice, defending the meek. Yea, these too, but they are not why we fight. Principles fail, muscles exhaust. For those of us who always hear the distant echo of steel against steel, it is the fight itself that calls us. The
challenge, the trial, the test.
To overcome ourselves, to bask in the
glory of sweat, tears, and stained and weary grip – this is why we embrace whatever the forge of life places in our path. Not to shrink away, not to navigate around, but to walk into that furnace, unafraid."
"With a hard gaze, the mercenary watched the pair of bandits looting the granary. He
didn't need to speak. The weight of what he'd seen, what he'd done, spoke volumes through those narrowed eyes. Each of the looters could see their own moral failings
reflected back at themselves, a wild story of dangerous possibilities flaring to life in their mind's eye. Slowly the men lowered the sacks and explained themselves, backing away. The mercenary knew that if he met those men again, he could count on their
heeding his demands."