There is no mistake.
The idea that an 'exploit' was a spell because spells, prayers, exploits, and psioinics were all presented in the power format is about as reasonable as claiming that a computer is a scented candle because you can find both listed for sale on amazon.
It was just a lot of overblown edition war propaganda. Don't bother repeating it again.
No it's not. It was not said negatively or derisively. If you can reference 3e or other editions without participating in edition warring then I (and anyone else) can reference 4e - either positively or negatively - and not be edition warring.
Like every edition (and game) it has good elements and bad elements, things that work and things that don't, and if we don't acknowledge the problem areas then we cannot learn from them.
Frankly, I no longer care enough about 4e to work up enough motion to even remotely "hate" the edition. (Since I'm more burned out with PF at the moment, I probably dislike that game far more than 4e at the moment.) It's no longer being produced so that war is over.
But if no one else can critically discuss 4th Edition with you, then in fairness I suggest you also refrain from mentioning any negatives of any edition was well, including 3e and 5e, to avoid edition warring.
The fact of the matter is that if you remove the flavour text and the term "exploit", "spell", and "prayer" from many, many, many powers and end up with identical effects. There was a LOT of design overlap in 4e powers. Not all, that is true. Many spells did very unique things. But there was enough overlap for this to be a relevant discussion point.
As point of fact, I ran a demonstration here a while ago where I pulled a bunch of random powers from the same 4e product (a Dragon magazine IIRC, solely because I could cut-and-paste rather than type), stripped out the relevant keywords, and asked people to identify which was a spell and which was an exploit. And no one got it right.
But again, the exact same claim could be said about the Book of 9 Swords and its maneuvers, which were also presented very much like spells - again, even going so far as to have 9 levels of power. So this is NOT a criticism of 4e per se, but of a style of design found in both 3e and 4e.
As it stands, it's no where near a viable option. Even in 4e, when h4ters were pretending that class powers were essentially identical, what exploits did and what spells did were too different to re-skin the latter as the former (the reverse might have worked, since magic could be so wildly diverse in what it did), and keywords made the difference between a Martial exploit and Arcane spell mechanically significant.
In a game like Hero, where 'powers' were genuinely fluff-free and generic, you could, indeed pull things like that. In D&D, not so much, and most definitely not in 5e.
While not every spell can be reflavoured into a martial exploit, that does not mean no spells can be reflavoured into an exploit. Obviously some spells have magical effects that cannot be replicated by any other method. However, there are many, many spells that can be altered and reflavoured as nonmagical attacks or utility.
For example, an eldritch knight could have the cantrips blade ward, friends, and true strike and the spells expeditious retreat, false life, jump, longstrider, shield, darkvision, knock, spider climb, and haste without any modification and present them as the result of exceptional skill.
And with a little DM approval and creative thinking many other spells could be employed, such as ray of frost being an ice arrow, disguise self being a talent with costumes, grease being an alchemical concoction, blur being quick movements and evasiveness, confusion being a disorientating blow to the head, and stoneskin just being really tough.
It's perfectly viable. And certainly far, far more balanced than homebrewing a new subclass with several dozen maneuvers/ exploits.
It's really quite similar, though 5e's use of spells in every class skews things towards the upper tiers. The Tier system is often taken as an index of 'power,' when it's really very much about versatiltiy. 5e neo-Vancian castes are /more/ versatile than the 3.5 prepped casters who ruled Tier 1. Conversely, a sub-class like the Champion is as one-trick (DPR) as it gets.
Versatility is certainly a factor. Which is why the cleric and other divine casters are potent. However, there are other factors such as the high AC and hp of 3e clerics, and the druid's animal companions which were as potent as PCs while also breaking the action economy. And little was done to mitigate the power of those classes, such as being restrained with the number of new divine spells added.
But, again, your argument assumes that casters in 5e are equal in power to casters of 3e. However, with repeated saving throws against status effects, concentration, and fewer high level spell slots this is far less true. The upper Tier 5e classes are nowhere near the quadratic power of 3e classes, with everyone being closer to linear in their power growth.
Versatility is important, but it's effect on power will vary from round to round, encounter to encounter, session to session, and even campaign to campaign. It's not as a solid bar to gauge potency. Additionally, just because the champion is a one-trick pony that doesn't mean it's not a strong class. Damage ends combat and dead is always the best status effect to put on an enemy.
As I said, ranking classes often reveals the values of the person doing the ranking more than accurate feedback towards the class. You seem to favour versatility over focus and devalue damage. Which is fine, but expect some disagreement.
It's easier to go into what they /can/ do in 5e: DPR. Unless you have some sort of magical ability, your meaningful contribution to the party's success in 5e is grinding out damage each round. Anything and everything else is unexplored design space that 5e could open up to new martial classes (the existing archetypes are too locked-in to DPR to expand them all that much).
… such as???
I know you want 'details,' but I don't much see the point, nor am I going to start designing examples. I'm not a designer, that's why I play published games instead of creating my own.
Then, to be frank, why are you in this thread? The intent, as outlined by the OP, is constructive feedback and ideas on designing a complex fighter, not just negging on the existing subclass. Willingness to design is implicit in the purpose of this thread.
Yes, the fighter is heavily design for DPR. Very nice. That point is rather assumed coming into the discussion. Further elaboration on that point is redundant at best.
That said, it's important to remember that 5e was built based on extensive concept testing and feedback. In some of the middle playtest packages the team added Martial Dice to the fighter and rogue that could be used for stunts or damage, which informed the design of the battle master. And the feedback from that was pretty decisive: people felt like they were wasting their dice when not adding them to damage. The versatility was there but people with loathe to use it and it felt like a trap.
A fighter subclass with a lot of versatility and utility will either have to trade out damage (and thus feel like a subpar option for many players and have situation dependant potency) or include the damage
We already have two past editions that did offer more customizeable or choice-rich or even balanced martial alternatives. All the examples you might want are there, and 5e's design is more 'open' than either, so they'd just be a start.
I'm not certain how 1-3e fighters were more customizable than 5e fighters, given 1e fighters had no options, 2e just had weapon specialization, and 3e had feats. The 5e fighter has feats
or ability score boosts, giving double the choices
and has subclasses on top. The 3e fighter was only more choice rich in that there was a multitude of splatbooks with feats. If just looking at the PHB there wasn't much.
