How about being able to do non-amazing things? Taking someone's limb off with an axe blow, stunning them with a mace to the head, slicing a tendon in their leg to make it useless, taking up an Iron Door defensive stance to be temporarily unassailable, parrying into a riposte... Anyone wanting to say they think D&D Fighters should have "realistic" capabilities needs to explain why they don't get those things. It's not because the game doesn't support severing limbs, stunning, disabling, because it does. It's just that they're required to be done by magic no matter how unrealistic that is. And frankly, a mundane Fighter being able to do those things would be amazing by D&D's standards, even if reality wouldn't agree.