I find it interesting you acknowledge the flexibility of the 3e fighter when the reality was the same as the 5e fighter...
The customizeability of the 3.x fighter was really quite remarkable. Most of his class features were in the form of 11 bonus feats (aside from that, he had full BAB, and slightly higher than typical hps). With a large list of 'fighter feats' (only a couple of which were fighter-exclusive) to choose from, the fighter could out-feat any other class in some fighting specialty, while leaving /all/ his regular feats from leveling to other things, if he so desired (or to master other feat chains, or mastering the first one much sooner than other characters could). Feats weren't optional, and you didn't sacrifice vital stat increases to get them.
So you could build a very high-damage charge build, multi-attacking build (via Great Cleave or WWA, practical multi-target multi-attacking, too), battle-field-control build, archery, mounted combat, etc...
Of course, if you wanted spellcasting you needed to multi-class - but then multi-classing wasn't optional, either, and the EK was an availabe PrC in 3.5, as well.
5e fighters are a lot more locked-in. They're multi-attacking DPR specialists. Style choice makes a modest difference to the exact context of that DPR (ranged vs melee, more or less tanky). Battlemaster doesn't open up a much greater range of options than everyone had by default in 3.5, and makes them limited-use. EK gives you a gish alternative if multi-classing isn't available (but in 3.5, it was, as was the EK PrC).
Now, admittedly, all that cool & awesome aside, the 3.5 fighter was still languishing in Tier 4. But it was still a lot more open to a much wider range of builds than the 5e fighter (or, 4e fighter, which was almost as locked into the Defender role as the 5e fighter is locked into that of Striker) - that it had the misfortune to be in the same game with 3.5 casters, not withstanding.
5e feats are 'bigger,' sure, but you can still compare that proportionately. 5e characters will typically get at least 5 feats over 20 levels. 3e characters typically got at least 7. 5e fighters get 2 bonus feats, at 6th and 14th, 3e fighters got 11 bonus feats, 1 at first, one at 2nd, and one at each even-numbered level.
Now, I'm not sure if it would really help that much to restore that proportion, whether that'd be to give the Fighter more ASIs (6!) - feats are optional, stats max out at 20 - or take them away from everyone else (1-2?).
So is your argument that a fighter cannot be skilled or proficient at dealing damage without GWM/SS and maxing their attack stat? If so, you're wrong. If not... well then you're in agreement with me.
Just pointing out that GWM isn't the only optimal option, let alone the only option. I don't necessarily agree that choosing between an optimal specialized feat and a sub-optimal one that is also generally available, is all that great a way of differentiating a character. And, I certainly can't agree that it's any kind of balancing mechanism when feats are, themselves, options that may or may not be available in a given campaign.
Of course, it's possible to factor out the impact of arguably 'overpowered' feats by simply assuming feats are not being used.
ASIs are still pretty important. Bounded Accuracy makes every point of attack bonus or save DC pure gold, so maxxing attack and caster stats is only to be expected - and sure to be done by the second or third feat at the outside. Having that extra +1 bonus in STR or DEX at 6th & 7th level, before moving on to other stats or feats (if allowed) later, is definitely one of the perks the fighter gets.
Yes and even when he was the best at something [MENTION=6774887]Ashkelon[/MENTION] claimed it didn't matter because of bounded accuracy...
You really do need to be more than just advertising-claim 'best' (no one has a higher bonus than me? Woohoo! I'm the best... and so is everyone else with the same bonus) to grab even 5e's DM-arbitrated spotlight-style 'balance,' yes. Like I pointed out, above, you need a pretty large advantage for it to show up meaningfully above the noise of d20 randomness. Expertise does that handily at higher level, for instance. Special abilities that obviate checks or do things checks can't are the other obvious way to get there.
So it's my fault for wanting to play a fighter?
Ultimately, for wanting to play a martial character that didn't conform to the 5 available archetypes.
For instance, I doubt you'd have been much happier with a Berserker or Champion than you were with the Battlemaster. A rogue would have obviously given you a very different experience, but just as obviously wouldn't have fit the character concept.
Or I should only play a fighter if the group has no valor bard, war cleric, barbarian, paladin, blade-warlock, Druid, or rogue with expertise in Athletics?Kind of limiting, don't you think? Especially when I stated that I typically enjoy martial characters in general but hate spell slots.
Or you could play the Barbarian or the Rogue with Expertise in Athletics, I suppose.