Do you know how many specs were utterly useless for most or all of BFA? And do you know how badly most of them got nerfed? Subtlety was viable for exactly one boss in Uldir and because it was good for that one boss Blizzard basically castrated that spec for the rest of the expansion. Subtlety got nerfed so hard that it was forever a bottom-tier DPS spec that never recovered.
And do I have to tell you just how ludicrously good Shadow Priests were from BoD to EP and how 8.3 Fire Mage is easily one of the most broken specs this game has ever seen?
How about in Legion, where Surrender to Madness Shadow Priests utterly broke Emerald Nightmare clean in half and where Affliction was STILL one of the best specs for the entire expansion overall? How Windwalker Monks were broken enough in 7.3 that 1 tank 4 DPS was a legitimately good dungeon composition?
Stop kidding yourself if you think this expansion’s balance is somehow worse than what existed in either BFA or Legion. There are some outliers but those outliers are nothing compared to what we saw previously.