Where to start? in Vanilla, you had the most freedom of playstyle choice in the history of the game. The approach was very hands off. Blizzard gave us the content and let the players decide how to consume it as long as it was within the rules. You could stick to one or two specific playstyles and earn the rewards for them, or branch out, but you were not penalized for choosing not to branch out. I could play however I wanted within the rules and not once did I ever feel like Blizzard was holding my hand and micromanaging how I play. The game, while still fun, was getting more and more limiting and restrictive with every expansion.
Then WoD came along and the go to design decisions have been to remove player choice and agency wherever and whenever possible and handhold players into a safe, Blizzard-approved, homogenized playstyle, either by removing features that add to player choice or using quality of life features as a carrot to incentivize players to explore the content the way Blizzard wants, but not necessarily the way they themselves want. Examples include: Removing legendary questlines, removing PVP servers in favor of War Mode, removing master loot in favor of forced personal loot across the board, attempting to force personal loot on solo runs of old content, sweeping GCD changes, attempting to remove flying, caving and adding a time gated one size fits all achievement with no room for choice or other options for unlocking flight, ability pruning, removing menu options that have been present since day 1 (ie. Hide helm, Hide cloak, etc.), removing buffs, removing mass rez, cutting substantial content intended to be included in expansions, restrictions on transmogging, removing reforging, removing currency-purchased upgrades, increased focus on RNG, removing PVP gear vendors, removing certain battlegrounds, removing the option to blacklist battlegrounds, attempting to remove waterwalking functionality from water striders and limit such functionality to their respective expansion content, implementing a camera distance nerf no one asked for, removing baseline abilities and reintroducing them as talents to pass off as new content, and whole host of other design decisions that have the effect of removing choice and agency out of the players' hands and into Blizzard's.
With all I've just said, I may sound like an old cynical bastard longing for the good old days who just hates the current game, but I assure you that is not the case. The current game is simply radically different from the game I fell in love with and remembered playing from 2004 all the way to when I quit in early 2016. The current game simply doesn't appeal to me. I'm not the target audience for the game anymore, and I've accepted that. I am waiting for Classic as that will provide me with the opportunity to play the version of the game that I am the target audience for as I remembered it, and those who like the current game, still get to keep it as is.
The current game does not appeal to me, and soon, when Classic launches I'll have the option to play a version of the game that does. Different strokes for different folks, I suppose.