Nintendo loves milking tech generations post N64/PSX era where game development got a lot more expensive.
10 years in the GCN/PS2/Wii type tier.
It'll likely be 10 years in the Wii U/360/Switch range of performance.
Switch's successor which should be like a PS4/XB1 but with DLSS and a few more modern architecture features will be something they're probably content with making games on for another 10 years. Once you get to PS4 tier graphics, honestly you achieve a certain level of visual fidelity that makes just about any genre game look good so long as you have a good art staff.
Switch 2 should be able to create graphics like this, probably fairly easily at that:
For a Mario game, Kirby game, the game's are going to start to look like pre-rendered promo shots Nintendo used to use, even for games like Zelda and Xenoblade there is a pretty massive step up.