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Nintendo faced a serious problem with both the Wii U and to a lesser extent the 3DS when they came out in that development times skyrocketed. One major problem they faced was that for much of Nintendo's first and second party developers it was the first time they had ever worked in HD game development and standards were higher in 2012 than they had been in 2005-2006 when the 360 and PS3 launched. They couldn't wet their feet with games of the graphical quality of early pre-Gears of War 360 games like other developers had. This ramped up development times, and games that could have sold the system like Mario Kart and 3d World couldn't come out in time partially as a result. I wonder if that's the reason NSMBU came out when it did so close to the 3DS version and seemed so half-assed. It was a good game, but everyone knew it could have been much more if the proper time and effort had been put into it, especially on the visuals. It was something Nintendo could get away with not making a graphical tour de force at the time. Games like Mario Kart 8, DK Tropical Freeze, 3D World, Smash 4, Yoshi's Wooly World and Kirby Rainbow Curse needed a lot of time and care to look as good as they did and still be playable.
The 3DS had a similar problem. It may not have been HD, but with its circle pad, glasses-free 3D, and near-PS2 level graphics Nintendo wasn't making as many 2D games for it like they did for the DS and those 2D games take a shorter time to make. The 3DS eventually benefited from not being in HD and having much better third party support so that it had a steady stream of games from late 2011 through 2016, but it could have used some more 2D love that first year to fill out the release schedule.
The Switch benefits from Nintendo now having years of experience with HD games development, being able to upres Wii U games to fill out the release schedule since no one had a Wii U, having nearly all of Nintendo's focus since the 3DS has not had that much support since 2017, and having pretty good third party support.
On an unrelated note, the GBA-DS situation is different from all the others. Nintendo continued to support the GBA because they thought there was a good chance the DS would fail and so the GBA would be their backup handheld with the built-in install base. That's part of why they didn't make the DS an official successor to the Gameboy line and called it a 'third pillar.' If Nintendo knew just how successful the DS would turn out to be then I think they might have called it the 'Gameboy DS,' or something like that to preserve the Gameboy brand.
