yep, depth of other classes increases the depth of your class and overall depth of the game as well
it was fun because you didnt do the same thing every game
sure, the fundamentals were the same (cc one target, damage another), but there was tons of cool class interactions that changed the eventual outcome of the game
like mage vs warrior lock druid in s8 was different because the druid didn't have dispel but the lock pet did so you could lock the warrior out of the game by keeping up r1 bolt/winters chill as dispel fodder while cycling nova drs (because they didnt all dr) and managed correctly you would shut him down.
then the next game is completely different because they have a dpriest healer who has dispel, mass dispel, and swd (and super fast globals thanks to a fuckton of haste), and you have to find a way to lock him out of the game otherwise the other team is going to be all over you (no cooldown on dispel) and if you are getting connected on you are fucked
then there are shamans who dont have defensive dispel but they have purge, shear ground, and bloodlust, which you also have to adjust your playstyle for
idk u get the picture, now every game plays out the same regardless of healer you just blink deep poly, get kicked, frostjaw, poly. the only difference is if its a druid you ring instead of frostjaw.