I'm sorry but this is 2018, Not being able to save back up on your save data is unacceptable, Especially with a franchise such as Pokemon, And like
WishIhadaManafi5 said, At least they could just make it like Alone in the dark to where It allowed for one copy of the game to be made as a back up and because what if my Nintendo switch break, What then we should just suck it up and deal with are lost save data and Pokemon, *No* And plus what if anyone didn't save the Pokemon they want to keep In the Bank or doesn't even have the app especially if it a really rare event Pokemon he or she may lose because of this poor decision to not let at least one save pre a let's go game be backed up on the cloud so yeah.
Oh and one more thing, I hope to Arceus a certain someone on youtube in which he will shall not be named doesn't even try to justify this as being good, Then again I want him to just to see the backlash he will get.