There's a slightly relevant response under "Dragging over your own computers is part of the fun of LAN parties. Why build them in?".

Ah yes, spending an hour getting setup then at least two peoples computers don't boot or the GPU doesn't work...then no one has or installed any of the games you're hosting. Good memories

Then we all stand around and help debug it

So much fun.... It's so much much fun that LAN parties have gotten bigger and bigger in the past 25 years... Wait, or was it the other way around that this is exactly why people just play over the Internet with each other?

It doesn’t capture the spirit of a group of friends getting together to play video games in a shared space? Or there’s a different definition of the LAN party spirit that somehow entirely precludes that aspect?

Like I could understand saying it misses out on the aspect of literally bringing your individual PCs, missing out on the neatness of everyone’s individuality as another commenter pointed out, but I don’t think they’d agree that the in person, gaming in the same place aspect is entirely precluded from “the spirit”

You are trying to deconstruct something, keeping part of it and calling it the same. You seem to be making my argument for me, so I have nothing to add.

A cyber cafe would be full of strangers though.

I think the spirit is people playing computer games with each other in the same room. I don't think it really matters who owns the computers.