I already said DS/GBA were a different era, where mobile tech like decent gaming, and internet didn't really exist, they were the only good form of good entrainment on the go, why do you think we went from 230-240 million psp/ds to 84 million psp/3ds it was mobile gaming/ entertainment making it's mark.
They weren't a "different era". The DS was born, literally, as the Internet "boom" got going. And it is the second best selling gaming device.....period. The 3DS faces more hurdles, yes, and yet, it still sells well. The hybrid Switch, which takes elements from the Wii U, DS/3DS, is breaking records. And the best you've got is, "yeah, but no one's buying Nintendo's platforms for Nintendo's games".
In a nutshell, no BS side-step, what else sells Nintendo's hardware if it isn't their software?