GH is a game which can take upwards of 10 minutes per turn to simulate 6 seconds of combat. I spent years of my life trying to get away from overcomplex rpgs. Pathfinder is a mess. Sleepovers spending 4 hours making characters and then whatever energy we have left trying to run the first combat.
The appeal of being a nerd is fiddling with minutiae. Conversations about parliamentary procedure, debates about art, Gloomhaven, all yammering obsessives trying to squeeze approval points out of each other by means of what ultimately comes down to aggression. I'll admit though that Gloomhaven handles this process, mass quarreling, gracefully, by encouraging competition between the mercenaries. Secret objectives, unlockables, perks, XP, all the rewards are best won via selfish actions like abandoning your teammates for gold. So there's something *fun* to argue about.
I like Gloomhaven enough to emulate it using Tabletop Simulator. For a game that is very much alike emulating a video game, I am emulating it using a video game. I felt embarrassed talking to my babe about this, the shuffling and parsing of minutiae, dragging digital cards around, muttering to myself and sitting hours in a simulation. My partner was like, why are you ashamed? "This seems totally normal to me."
"Shut Up & Sit Down" has a good review which covers the benefits and frustrations of Gloomhaven, and the reviewer summarizes his affection as a feeling of "warmth" when extracting or putting away the complex innards of the box. Very much the nerdy management of minutiae, but let's also give credit to the game for creating continuous iterations of interesting puzzle-combat.