They aren't resolving the problem, just delaying it. They are increasing the development time and costs....but just years later. Seems to me that is basically Nintendo slowly heading to that dead end, but just more slowly...
You see, this is where game design comes into play.
A game like Captain Toad will only marginally need to improve on high end hardware coming out in 2030, becauase of the way the levels are designed.
Meanwhile to compete for the consumers money in the AAA space, it's all about scale. The more stuff you can fit into your game, the bigger you make the world, etc.
The game with the most realistic facial animations, highest quality voice acting, etc. will win. And these things are directy related to how much you are willing to spend. The guy who spends the most wins.
Same with Splatoon compared to Battlefield. The latter is now pushing destructible environments and organically appearing events like entire scyscrapers collapsing. That's pushing alot of horsepower, but a minimalist game like Splatoon will never have that issue of demanding bigger and bigger dev teams. The graphics will merely get shinier and the resolution bumped up. Nothing fancy.
Mario Kart 8 you could argue went from flat in the past to fully realized 3D tracks, with alot of twists and turns, up and down, inside out. Yeah but where do they go from here? There's not much else you can do, so they've already reached the upper ceiling for this franchise. From here it's smooth sailing.
Same with 3D Mario if they go for obstacle course style linear levels.
Zelda is a different because it seems like they are keen on, at least superficially, mimic open world games. But how does a 3D Zelda dungeon differ from OoT to SS? It's the same in scale but prettier graphics and cool effects.
Enclosed environments > open world
Minimalist artstyle > photo realism