Thanks - feared as much. Annoying if you want to change back and forth between games / are prone to losing things. I don't think I'm spoiled from years of using Steam - that just seems a pretty logical approach.
I have a Switch storage case that has a flap for maybe 10 cartridges, handy for keeping the little fuckers in one place.
Its the official one from when Switchs 1st dropped, so unsure if it obsolete.
Nope. Need the cartridge if you want to play it.