In Hell

Infernal Descent takes place in Avernus, the first circle of hell according to D&D lore. Players are provided with a safe haven there in the form of your base of operations, a stronghold that was pulled down into hell due to a curse or something, but otherwise the environment is (understandably) very hostile.

I think it's always challenging to make players spend extended amounts of time in zones that are by their very nature extremely hostile and unpleasant, because if the environment truly lives up to its reputation, no amount of rewards will make people want to hang around.

Avernus, too, largely manages to deliver on what you'd expect from a circle of hell, with a slightly grating soundtrack and everything being tinted in unpleasant shades of red. Even the mobs contribute, as the Erinyes' screeching for example is a proper pain in the rear. It's bearable for the duration it takes to get your weeklies done and the gameplay is fun, but unsurprisingly the first circle of hell is not a place where I'd like to spend more time in the long run.