Battle master existing has been a massive detriment to future development

The subclass itself is fine, plenty of people enjoy it. No problem there.

But we just got a book full of magic options, and we're not getting a martial equivalent. The monthly D&D Beyond drops give us new spells, and never new martial options. The reason why is obvious - you can always add new spells, but there's no way to expand martial options the same way.

And the main reason for that is there are no maneuvers or anything. That's how D&D originally solved martials lacking interesting choices, a couple of decades ago at this point, but in 5e they named a battle master feature the same thing despite being a minor, really limited system and only belonging to one subclass.

Now whenever you mention the idea of adding maneuvers to the game, people immediately jump in with "uh, we don't need that, haven't you heard of battle master?". Which is like saying rune knight exists, so we don't need spellcasting classes.

So yeah. Subclass itself is perfectly fine, genuinely adds much more than your average subclass really, but it existing at all has hobbled and blinkered both design and discourse regarding martials. I'm fairly sure that if it had never been created at all, we'd have gotten some better solutions by now - but it looks juuuust enough like a solution that people instead say eh it's solved battle master exists.

I don't think we need new combat options for martials. But right now all martials can do is combat. It would be nice if there was a niche where casters were much worse than martials out of combat.

Every day I look at Tome of Battle (released in 2006) and wonder "How did we go backwards?".

Por que no las dos?

Your title is misleading, I think. The decision not to support maneuvers is a massive detriment, not the existence of a subclass that uses them.

I mean they could have done better in the 2014 PHB, but it could have been improved and expanded to other classes since then. They made the affirmative choice not to do that.

The Tome of Battle was so strong it made the CR system unusuable haha

So true. I've just never personally been in combat as a martial and wished I could be a caster. My gimmick is axe.

I desperately want new combat options for martials. The joy of playing any game, to me, is making meaningful decisions, and that just isn't possible when I only have one viable option (the Attack action) in the vast majority of situations.

Spellcasters are fine because, even when their spell slots are spent, they have cantrips to fall back on as a round-to-round action option. But martials just don't have that. At best, they can use grapples and shoves, but in many encounters (and for ranged builds in general) those options just aren't viable.

Tome of Battle was weaker than half the classes in core. The fact that it was strictly superior to Fighter was more of a Fighter problem.

I think you're right that bottling the manuevers up in BM probably looks like a mistake retrospectively.

They could've had Extra manuevers or unique manuevers. Not sure, but I resonate with your point I think.

Purely from a design perspective, as a player I really don't mind.

Vanilla clerics and druids did it first honestly

I'm gonna be real, the existence of Origin feats are an untapped potential for further maneuver development.

An Origin feat that grants X maneuver dies, say d6s. X being your proficiency bonus. And allowing you to choose three or so maneuvers from it would not be too egregious in power.

And would allow you to play with Maneuvers WITHOUT needing to worry about Battle Master. This way they can add move maneuvers and everything.

I, personally, would've liked if they stuck to the DnD Next playtest and the fighter class in general had maneuvers.

The Battlemaster could've then been differentiated by being able to inflict more damage with maneuvers, knowing more maneuvers than the average fighter, having a greater number of uses per short/long rest and even chaining maneuvers together at higher levels.

There was a lot of design space for the fighter that was left untouched and further unremedied by 5.5e.

Its not about wanting to be a caster, its about giving ways to interact with the combat on your turn outside of just "i roll. Does a 9 hit? I roll. Does a 15 hit?"

No it just turns out that if more classes get buffed to start to maybe compare to wizard, the whole game breaks, for some wild unknown reason no one understands

/s