While I put an epic number of hours into Marvel Heroes (only recently did Helldivers overtake it as my "most hours on Steam" PC game), honestly I think it has Too Much Stuff now. Too much loot, too much crafting components, too many inventory pages to sort through, too many areas to play in to the point that when I revisit, as God as my witness, I don't know where to go or what to do anymore. If I play the game 10 minutes, my inventory gets completely overwhelmed.
I actually preferred the game early on, maybe for the first year, because I had a handle on what areas to move through and inventory wasn't quite as swamped every 5 minutes.
Isometric ARPG speaking, that's about the only one I've played that's trying to fit in the mmorpg space.
There's so many ARPGs people can play for free, I think it's difficult to convince a massive playerbase about the need for one with monthly fees or a cavalcade of F2P stuff.