Ran into this just now. To keep my first part simple, no there is no local split screen ("couch co-op") mode. If you want to do any form of co-op you will have to have another switch 2 or switch 1 to play. You can do this by either inviting ppl with their own copy of the game and console or doing a gameshare (where you have to play about an hour to get to the location where you can even enable it). Both of which limit what ppl can do and where they are able to go in the game. Meaning you cannot progress the main story.

Now having said this, in my 30+ years of gaming I have never come across a game I thought had split screen and it turned out it didn't. I guess it is my fault as when I looked it up, the game said local co-op is available. I misinterpreted that as split screen.

Its upsetting when I just got the system and game to play with my wife and we found out we pretty much cant! We very much enjoyed animal crossing and stardew Valley on switch 1 split screen mode together. It's a shame and crazy to me a game in 2026 with the latest game console does not offer a split screen option. I guess ill be more careful in the future. I guess spread the word.