Warcraft
Action
RPG
Diablo
Diablo 2 creator says players treated the action RPG like a "lifestyle game" because it was fun, and MMOs like World of Warcraft had more to do with starting the live service trend
Diablo's moreish tap-and-loot loop definitely has a lot in common with some live servicey features, which are mainly aimed at keeping people on the seasonal hamster wheel forever, but the series' co-creator doesn't think Diablo was designed with the same intent.