StarCraft 1 let you take your computer to anywhere and connect on the LAN with anyone, or even dial-up directly to your friend's phone number.
In StarCraft 2, Blizzard like every other corp wanted to see and control everything we do so you have to go all the way through the internet and lag even if you sit right next to each other. lol if the connection goes down!
Even on the PS5 when I hand a visiting guest the throwaway DualSense I have to bump through a clunky UI of choosing a user or "Quick Play" and wait while it spins up a whole new home screen and other crap for them, and then warnings about DLC or whatever in Mortal Kombat etc, just to have a short 2 minute beat-em-up session.
Sigh
Yeah, not to mention that you even needed to connect to their servers to play the fucking single player campaign. I hated that so much, and then it more or less became the standard for many AAA single player games to come...
"Quick Match" and ranked queues destroyed multiplayer gaming for me.
There's a security problem (and hence legal liability) when two people know each other's IP addresses.
There's also a complex networking situation when people are behind NATs, firewalls, etc.
To be fair, multiplayer via LAN is such a marginal feature nowadays that you can't really blame the companies for not supporting it. You don't really need "greedy corporate fucks" explanation for this; it's just that you don't want to develop, support and test features that maybe 0.1% of the user base is going to use.