Art direction in general is about ensuring that resolution and assets/detail are balanced out and work together. 95% of the time Diablo 3 looks near perfect on Switch but there are times when you are reminded that the character model “ought” to be visible in a higher resolution. Skyrim VR now looks unpleasantly crude after playing with the upgraded visuals on other systems. That's because you've taken a game that was art-directed for one set of specs and then scaled down to tech so that it can no longer match that direction. Those cases are not common, though, because we don't often have a reason to step back a generation in graphics reproduction. Usually art direction and techological power move in lock step.
When I bought a new gaming PC in 2016 I thought that I would be brute forcing siginificantly better graphical results, but it's not true. There are diminishing returns in higher frame rates and most games’ performance doesn't scale beyond a certain point. Sure, everything looked fantastic when we first moved to digital outputs on consoles and could see games at 720p but even today when we have resolutions well beyond 1080p we are not seeing equivalent strides forward ... which is why the Switch is “good enough” for most purposes. Sure, resolution makes a difference, but it doesn't make all the difference.
So, yes, detail/effects/assets are what really counts (we could do completely without 4K gaming and I'm in no hurry to get there) but resolution counts for more than we think it does simply because we are unlikely to go back once we reach the next plateau.