Fans want them to keep making hardware and people who might buy 1 or 2 Nintendo games want them to go third party.
"Buy Mario Kart 9 and you get to drive as Ratchet in four tracks designed only for the PS5"
"Buy Mario Kart 9 and you get to drive as Master Chief in four tracks designed only for XB2"
"Buy Mario Kart 9 on IOS and you get to play as all the Angry Birds"
........that last one was tough to write...ugh