• The lack of an open world is a big one for me. All those square areas are immersion breaking.
• Bags, that contain bags, that contain more bags, that are full of worthless junk. Loot needs to me meaningful, I'd rather loot nothing than all the garbage I'm currently looting in this game right now.
• Every skin displayed in a wardrobe, including those that are not currently owned, as well as ways to get them, like in WoW.
• Lack of unique skins locked behind meaningful or interesting content, like world bosses, or very long questlines. I wish there were more of those unique quests like the one to obtain the Gryphon mount, that could reward unique skins for gear, gliders and mounts.
Maybe a very hardcore puzzle jump could reward a specific hat skin for example. Or a hidden questline in that area of the world would grant you those gloves that you can't get anywhere else. For example, in WoW, the "Neurosurgeon's Tool" is a unique dagger skin that looks like a cleaver, and you can only unlock this skin by completing a level 35 quest. This kind of thing would give players even more incentive to roam the world and explore.
• Lack of PvP content, like 15v15 battlegrounds, a bandit/mercenary system for open world PvP, and duels. These features would only be enabled in new PvP servers of course, to leave PvE players enjoy the game without interference.
That's for me. What about you?