I definitely think Lets Go was always a 3DS game. Hot take here, but I think at some point lets Go was intended to be the 3DS' swan song game, for the anniversary in 2016, but it didn't pan out because Pokemon Go didn't pan out either. Like this would have made A LOT of sense in 2016. It would also explain why SM and Gen 7 feel a lot like it was intended for a single screen device, and why it has a lot of cut corners. At some point, they switched platforms, with Lets Go coming to the Switch, with SM being released on the 3DS instead. I am fully serious, I think SM was planned for a launch on the Switch in 2017.