I wish we could return to a Wii U like functionality where the switch could be used as a second screen when undocked. That was a really nice feature in games like Zelda where the controller in your hands displayed the inventory or a map.
Yeah I played BOTW on the Wii U and remember at some point I just stopped bothering with the handheld screen.
I can't remember what game it was but I do remember having one game where the handheld add-on provided some functionality that seemed useful/fun. So it is possible, but much like the original wii's motion sensors - it is much more likely that developers will stumble across a bad application of the tech than a good one
BOTW didn't even leverage the Wii U gamepad. The Wind Waker and Twilight Princess remakes let you equip items with it, and I think that was the original plan for BotW too, but they removed the feature likely because then it would have an extra feature over the Switch version that launched at the same time.
Much like with the failed Macbook Touch Bar, I don't think it works having to look away and focus on another screen while playing a game.
Also like the Macbook Touch Bar, now you have a whole other thing developers have to target and test for an end result that should just be possible yet more efficient in the main app.
Take inventory for example. Instead you could just make it frictionless to open inventory in the main game and create quick-swap slots. Tears of the Kingdom is a good example. Swapping out arrows mid combat by looking at your controller would not be an improvement.