Mustrum_Ridcully
Legend
It is not boring, because combat is ultimiately a very interesting part of the game. If it wasn't, there were fewer rules for it. Even "story-telling" games that supposedly focus less on it have complex rules to handle combat.Reading: It's fun and informative. Pull those dusty old tomes of your shelf and take a look. lots of good stuff in every edition of (A)D&D.
You seem to have a vry narrow definition of "useful", one that I don't subscribe to or even think is meaningful. I mean, if the definition of "useful" is limited to combat, that means combat is the only thing that matters in D&D, which would be a really sad, boring thing.
But anything "important" outside of combat can apply to any character. What out-of-combat options are unique to the Fighter and infeasible for a Wizard, a Rogue or a Cleric? If there were more "meta-game"/narrative/story-telling mechanics to each class, then you might have a point, but there aren't.
Maybe it was different in earlier editions, with the inconsistent skill system that treated skills with different subsystems for different class (like percentile skills for rogues, Non-Weapon Proficiencies and so on.) But we got away from that, maybe for the sake of "verisimilitude" and believability.
The name of the class is Fighter. I would expect him to be useful in combat all the time. I can get why a Rogue, Cleric, Wizard, Bard, Monk, Archivist, Scientist, Engineer, Wheelman, Warlock, Thief, Priest, Rat Catcher or what-you-have might not useful in combat at all levels (or at all). But a Fighter?