Fists of Fire and Fists of Wind are only important to DPS because you need to have them up, not because they're good skills. Fundamentally you only want to be in Fists of Wind for 99.9% of the fight and sub to fire for the first 3 GCDs and the last SSS>TK. Which functionally makes it about as useful as Tornado Kick as it's ever been. There is no choice between the Fist Stances, they're an illusion of choice that shouldn't be in the game and that's what they've always been, but for some reason there's two traits tied to it.
You're absolutely wrong on Black Mage, it has gotten a new Single Target GCD Skill every expansion that see use every rotation cycle (Foul and Xenoglossy). It also got Despair this expansion. Dragoon on a technicality got one as well in the form of Raiden Thrust, but even if you don't count that it has consistently gotten new attacks to use every expansion such as Nastrond, Miragde Dive and Stardiver. Monk has gotten two "New" skills that we actually get to use on a regular basis, Elixir Field at 54 and Brotherhood at 70. Everything else has either been a top end replacement for something they removed from the kit at the bottom end or an overly situational piece of junk.
They haven't tweaked Monks flow at all, they've actually introduced GL4 which is something that should have required some changes to its timers and literally didn't change any of it's timers so the highest DPS rotation involves dropping a buff for its reapplication.
They haven't given Monk a lot of attention, they've neglected it and ignored player complaints consistently from expansion to expansion, introducing new actions that were completely redundant with old actions that could have just been improved , and let those problems fester. It was so bad that Yoshi-P apologized about Stormblood Monk during the lead up to Shadowbringers, but surprise surprise on launch very little of what people hated about Stormblood launch had actually changed. That's not attention at all. Even if Monk is performing highly now, that doesn't change that it's kit is and has been a junk heap for an expansion.