GBA was kept alive for years after the DS was released. PS2 was kept around for four years after the PS3, and even had a major release in 2007 with God of War 2.
This stuff happens, and if Nintendo can manage it while still keeping up a strong slate of Switch titles, I say let them. I mean, I still own mine. There’s over 72 million of them out in the world, and Nintendo wants to move another 4 million this year.
The Switch is still $300. It’s too big to really be considered pocket-sized. As I see it, there’s still a market for a cheap, pocketable portable device worth supporting with occasional software. It’s not like they’re putting the next Zelda or Pokemon on it or something.