Not at all, balance is a positive quality that games have to varying degrees.
The Martial/Caster Gap is an example of quite significant imbalance in D&D, generally, and 5e in particular. It in no way implies that the problem lies with the fighter. Nerfing casters into the ground could also close the gap.
In 5e, specifically, IMHO, nerfing casters would be absolutely necessary. 5e went too far in restoring OP spells and expanding caster flexibility, while further removing restrictions from casting rather than adding back restrictions that formerly attempted (unsuccessfuly) to balance that power/flexibility. That 5e also gutted the fighter is almost a minor consideration, especially since every edition has approached fighter improvement by first taking away everything cool the fighter had in the prior ed....
...ah, wait, I see your point!
Yes, scrapping what cool stuff the 5e fighter has in order to try yet another way of balancing it would be unfortunate. Balancing the fighter by (in addition to nerfing casters) expanding options, so players who really wanted to could still choose the kinds of straightforward multi-attacking single-target DPR specialists they are would be better than scrapping everything and starting over.
Really, bringing back everything cool fighters have ever gotten would just be a modest start.