What's the point of Fighters (instead of Paladins/Barbarians)?

I started a solo playthrough as an Inquisitor and, I've gotta tell ya, being immune to all of the nastiest spells is NICE. On top of that, my Paladin save throws are so high that I can resist almost everything thrown at me that I'm not already immune to.

So my question is, is the extra damage you get out of a Fighter worth losing all of the free immunities you get as a Paladin (or a Barbarian that uses their rage ability)? Personally I would say no.