Part of me honestly wonders if you really need graphics much better than the above. That looks like a fairly realistic depiction of a forest. How much more is needed? Having a game that looks just like reality isn't going to be great anyway IMO.
For a company like Nintendo I almost think the above would the maximum type of horsepower they'd ever need. Their games would basically begin to look like the CG renders they use.
It's not about needing though. Zelda has stolen me away completely from HZD. Doesn't matter what it looks like (it's beautiful too) as long as it's good enough to sell the illusion of a living breathing world. Keeping it a bit abstract or stylized makes it easier to draw attention to 'oddities' ie hiding little puzzles in plain sight. Make it too realistic and you need those ugly outlines to highlight objects you can interact with.
Ofcourse rendering BotW in 4K60 would be welcome, and there's no shame in better textures or running the game in VR :)