man, I really miss LAN parties. :( 8-12 hours of just straight concentrated gaming fun (after the requisite 1-2 hours of setup and driver tweaks and server configs and optimizations), zero worries about outside responsibilities ...
To be fair, the niche has been filled by the internet, easy voice comms, and MMORPGS or shooters, or even tabletop games. Assuming i can work out schedules, it's straightforward to get online with a group of friends and play, and i don't have to seatbelt a 17" CRT into my car's front seat. Is something lost? Maybe so. But something has also been gained, as i can and do play with friends out-of-state.
You can still do that. Honestly. Maybe not for all day, but telling the fam "I have trolls to kill, bring me snacks and let me do this!" Is a thing, so long as you don't overdo it.
In my early married life, we actually did a couple of lan parties where we brought the significant others, and the non-players hung out and did chat/snacks/movies. That wasn't horrible, but the group was very integrated - we were all college friends.
@Biggles I think for me it was the dedicated purpose of going to another space, at a given time, and knowing this was the only thing you were doing all day (or night)