Some Switch games do not support cloud saves “to ensure fair play”, Nintendo has said.
In a statement issued to Game Informer, Nintendo said cloud saves in some games would make it possible to regain items traded to other players or cheat when it comes to online multiplayer ranking.
Currently, the Nintendo Switch does not have a cloud saves feature. You can’t even transfer save files via USB. But the Switch will soon get cloud saves via the premium online membership service – the problem is it’s not for all games. Upcoming Nintendo Switch game Pokémon Let’s Go Eevee & Pikachu does not support cloud saves, for example. Nor does competitive multiplayer shooter Splatoon 2.
Source: Eurogamer Nintendo: some Switch games don't support cloud saves "to ensure fair play"