Originally Posted by
Belloc
OP: Here's what's changed: Pretty much everything. Classes changed from being very poorly designed in Vanilla, to better designed in TBC, to well-designed in WotLK and MoP, to... well, I can't speak for class design after that, other than for a couple patches in BFA, where I enjoyed my warlock and prot paladin designs.
Raids changed from Vanilla in that they went from 40 players to 25/10 players, to flexible sizes with 20-player Mythics.
Raid bosses changed from being basic-bitch bosses in Vanilla, to slightly less basic in TBC, to relatively complex in WotLK and onward.
Raid loot changed from being very sparse in Vanilla, less sparse in TBC (and abundant when you consider badge gear), common in WotLK (especially considering badge gear), common and fun in MoP (I rather enjoyed thunderforging as a concept), to, once again, sparse/tedious in SL.
Addons changed from being basic in Vanilla, less basic in TBC, overpowered (and then subsequently nerfed) in WotLK, and better designed and featured as the game has gone on.
Content has changed from being quests, world-PVP and battlegrounds, basic dungeons and raids in Vanilla, to all the same plus arenas and heroic dungeons in TBC, to all the same plus daily quests and hardmodes/heroic raiding in WotLK, to more daily quests and LFR raid mode and rated-BGs in Cata, to all the same plus large amounts of daily quests, scenarios, flexible raid mode, pet battles, challenge modes, brawler's guild, proving grounds, and probably more... and subsequent expansions had mage towers, or expeditions, mythic +, etc. Content has changed/increased dramatically over the years.
And that's just the things that were obvious to me. The game has changed immensely over the years.