Civ 6, the whole Picross lineup on the switch (emulated ofc), Cassette Beasts, Minecraft Java (which can be a pain to setup but once its good its good), Halo MCC apparently has a new split screen mod.
You get a lot with a switch emulator due to all the fantastic first party games by Nintendo.
Also look into Nucleus Coop.
Civ 6, the whole Picross lineup on the switch (emulated ofc), Cassette Beasts, Minecraft Java (which can be a pain to setup but once its good its good), Halo MCC apparently has a new split screen mod. You get a lot with a switch emulator due to all the fantastic first party games by Nintendo. Also look into Nucleus Coop.
Tl;Dr: try Cassette Beasts