ive played wow casually since tbc but this past season was the first time i tried to do some relatively "hard" content and got keystone master, even though i was pugging it it was a super rewarding experience and i enjoyed it a lot (season 3 destro lock lololol), honestly felt comparable to when i first got over the fear of not being good enough for tf2centers
gameplay can be super rewarding when you actually play well, but like tf2 theres a lot of default settings and ui elements that make the game waaay harder than it should be
id recommend watching a few videos on keybinds, ui setup and weakauras if you want to give yourself a leg up
wowhead/icyveins guides are also very nice and help you wrap your head around setting up your character properly
ive mentioned it in this post already but a lot of the more exciting content is actually relatively accessible, for me i had to get through the exact same mental hurdles i had to get through while getting into 6s, which was honestly a cool experience to have again 9 years later
theres not much of a downside to just trying it out and seeing if it sticks, theres a reason a lot of people love wow as much as they do