What i think went wrong for Nintendo is that the continued success of the Switch made them far too complacent when it came to start developing games for the Switch 2, instead they continued too long to only develop games for Switch, which lead to a shitshow when it came to Switch 2 game development.
Nintendo isn't making craploads of Switch games because the Switch is successful. Switch is successful because Nintendo makes craploads of Switch games. Not trying to jump on you, I just hear this take a lot.
Maybe it's just the word
complacent that bothers me - maybe you're right that Nintendo was late to the transition, internally. But Nintendo internal teams have never made
fewer games per year in their entire video game console lifetime. They're not overfocused on Switch
Like, just for comparison - the Wii had 25 games that were developed primarily by Nintendo internal studios, between
Wii Sports in November of 2006 and
Mario Party 9 in April of 2012. That's a game every 2.6 months, while
also developing for the handheld consoles - another 11 games!
By the time
Dark Moon HD releases in June, the Switch will have 30 games developed primarily by their internal studios, over the course of 85 months. That's a game every 2.9 months, despite the fact that there is no GameBoy/DS/3DS to support anymore.
The Mario Kart team used to make a Mario Kart every 3 years! One on the TV, one on the handheld, and then back. 2D Mario Team? Even faster, same thing. 3D Mario? 2007, 2010, 2011, 2013. If you look at it this way, these teams were jumping between consoles all the time - and now they're all down to a game a generation. There is plenty of room to believe these teams transitioned to Switch 2 after making their once-per-gen entry, the same way they'd move to the handheld before jumping back. If Nintendo was putting these devs back in the Switch mines prematurely you'd expect more games from those teams.
But really, the cadence is lower. It's just that with
Fire Emblem, Pokemon and even
Mario versus Donkey Kong no longer handheld exclusives, the pace can stay the same while the number of games received is higher. And Nintendo has really worked to get their partner relationships in place, with
Pikmin, Metroid, Smash all having permanent outside teams, the way the Mario spinoffs have.