It may not be completely over, but it’s far from the focus of multiplayer gaming.
Many games that used to offer couch multiplayer (e.g. split screen) options no longer do.
The upcoming Starfox remake is a great example (no split-screen multiplayer options, where the original did).
I can’t remember the last time I’ve seen a 4-player split-screen FPS (like Goldeneye 007).
Can you find games that offer couch multiplayer? Sure. But it’s not something that is a priority, particularly for most mainstream games.
(And as a side note, LAN parties are also largely a thing of the past.)
It's a past that's readily accessible in the present and has carved out a niche in the gaming scene. Is that really "past"?
I fully intend to delay my kids' introduction to online play in favor of in person multiplayer as long as possible. I have had up to four 6-8 year olds playing Minecraft together on the LAN on my kitchen table already.
It's part and parcel of my whole "good screen time vs bad screen time" beliefs.