This is the same old tired drivel that has been reposted and repackaged over and over by a bunch of people that don't understand games have to evolve and change as nearly everything in life does. Trying to sell vanilla WoW in todays day and age the game would be a massive failure. It's slow paced, the quests are about as boring as they possibly could be, everything takes super long, for some specs pulling more than one mob means you die over and over on some quests/areas. If I had to play vanilla WoW today I would not play WoW because vanilla WoW sucked hard. I loved it back when it was new but it is not something I'd want to play again anymore. That's how games evolve and change.
WoW is fine. The game is still a good game. It just has more ways to experience the content than before instead of having one route you have to take which usually led to content becoming obsolete. Some of the same people in here complain about having the same content repackaged on higher difficulty.. why is that a bad thing? Like I can raid on my warlock and get gear that way. On my paladin I can do dungeons and slowly increase the difficulty to get better loot as my gear gets better. To me that's more fun than grinding the same boring heroics for badges or points to purchase set ilevel gear. I'd rather have more options than less options. I don't want to go back to Wrath where I had to raid 5 nights a week to have decent gear by doing 25 man and 10 man. I don't ever have to step foot in LFR to get items and gear thankfully because that is the last thing I want to do in this game. I'd rather have world quests then one little daily hub where you have to do the same quests over and over every day this way I can choose which ones I want to do if any. The weekly events let you mix it up if you so choose.
I honestly don't know how anyone can say Legion has no content with a straight face because I can always find something to do.
Despite everything I like about the game there are some issues imo. The class design could be slightly better for some classes(this is always a subjective preference though). I don't always like the RNG with loot, and I wish AP was easier to get on offspecs although the recent change to AK research time should help tremendously.
I'll be honest most of your list is a just a bunch of tedious boring chores you have to do to play the game that was around when the game first launched. The fact that you can write stuff like going to class trainers to learn spells as being a positive for the game really makes me question just about everything you could possibly say.
In short I find most of the people that post on these forums to be in all honesty not very intelligent and when you read lists like feeding your pet food or learning spells from trainers as being highlights of how the game used to be it's really hard to think you know much of what you are talking about.