Are you trying to insinuate that fighters can emulate Polymorphs, invisibility, teleportation, protection spells, and such? Because they cannot, and that doesn't even count clever things like walls, monster summoning, etc. etc. etc. which can be of huge strategic value when used correct (and some of which can trigger damaging conditions on monsters which are relatively unavoidable to them, and don't necessarily fall prey to resistance/immunity or even saves).
As a past (and present) master of the art of manipulating the spell list to my benefit, I assure you, fighters are not in the same league, not even playing the same game. Yes, when their one area of expertise comes up, and it does pretty often, they're quite effective. Otherwise? Any other character of any other class would do as well, and more likely better.