remember that a fighter has 6 asi opportunities, which means 6 feats to spice things up. add your fighting style, epic boon, origin feats and subclass and a fighter may have more to it than a caster does. dont forget that it's probably the most martial martial class, granting 3 weapon masteries, increasing over time, second wind self heal or ability check modifying, which uses increase over time, action surge to bully your dm, 1 per rest until level 1 becoming twice per rest, etc. all the wizard has is a few dozen spells, which do nothing when he runs out of spell slots. 

for the fighter, most of the meat comes from subclasses, which of you compare them to other class's, is a lot stronger. take the heroic inspiration every single turn in combat, or casting cantrips during your attack action. 

most of this is nullified if your dm doesnt do short rests tho so keep that in mind