Blizzard's "Delves" in World of Warcraft have been incredibly fun and rewarding, or horribly painful and depressing, depending on which class you ask. WoW has been designed all up for group play for the past two decades, which is clearly making its new solo dungeon "Delves" a nightmare to balance.

source https://www.windowscentral.com/gaming/world-of-warcraft-war-within-delves-review-solo-play-fun