but it’s just too much. (btw I played from vanilla to MoP.)
After paying $100 au I’ll have to download and configure and practise loads of addons. Then there’s the grind to max level. Then there’s learning the abilities and classes. Then there’s learning dungeons, then raids and mythics, while dealing with elitist and toxic players …
I did consider it. Really.
It sounds a lot, when you put it like that.
But Addons don’t take much time, unless you want them to. There are people who, I would swear, enjoy setting up their screens just so more than they enjoy actual gameplay! Slap on a dozen of the basic essentials, which you can do through a handy-dandy automatic downloader and updater like WoWUP-CF, and you’re good to go. Add and tweak more later to taste. Blizzard have made the whole screen editable, and quite a few people no longer find they need UI addons as a result.
There isn’t a grind to max level, really, since you get one Level 70 boost as part of your purchase, so you will just be levelling through the new expansion from 70 to 80 with everyone else. 10 hours will probably be the average, though the speedies will doubtless do it in half that. And I expect that will be enjoyable, not a grind. It’s the one thing in WoW I find guaranteed to be enjoyable (at least the first time; let’s not talk about alts, of which I have too many 
)
When it comes to learning your class, I’m with you. Depends a bit on how well you need to know your class, though. Enough to get around the world, and do Normals, Heroics, LFR, random BGs, and basic Delves is practically nothing, certainly for someone who played before. If you’re aiming at high M+ and Heroic/Mythic raids, then yeah, that’s a thing. Needs work for that. Ditto with learning the M+ routes.
Loads of addons…?
The point of making sure your UI works for you isn’t to start with addons, it’s to get add-ons as you encounter a need for them.
Outside of that I dont know what the issue is, you list all the stuff we always had to do in the game