Lan-game networking benefits?

Today all games are geared towards playing online.
What I’m wondering, what if all players connect via Lan having 1gb connection to the server.

How much more can you cram out of the networking?

Lets say you have the fps shooter example… as that is what we have, generally fps-games are capped at 64 players(with exceptions ofcourse).

How many players could you run on 1 dedicated server over a modern Lan?

That’s not the only issue though, a big part of it is memory management. Many MMO’s limit things because there can be too many varations of things that have to be loaded into memory.