I was meaning that a lot of late SW1 buyers will be of younger kids that will have migrated to wanting PlayStation by the time they'd be ready to upgrade, and economics of the hardware that is sitting in the GB, GBA, DS, 3DS slot that isn't reaching those mainstream prices could cap the target market IMO.
The hardware is already dated, and that situation is only going to become a worse comparison against PS5/Xbox as we get further from launch.
The point about the Wii was that the console saturated its market, much like I believe SW1 has, and outside the Nintendo handheld core (50m-70m) and core gamers wanting to have all devices I can't think of how the SW2 differentiates itself from SW1 in the casual market that made up a lot of those Wii and SW1 sales.