I am having a hard time putting my beliefs into words but I'll try. First off my father and my DW like seeing someplace new and my Mom hated going on side trips. I don't worry about much when it come to planning routes, grades in the road lead to summits and beautiful vistas, switchbacks going up or down a mountain just means it takes a little longer(with the exception of severe roads not meant for anything but mules and 4X4's) and lets me see a little more of the area. With one or two exceptions the roads of today are pretty well signed for low overheads and the like. Shear drop off scared the bejesus out of my mother and my DGD, I don't fear them, I love HWY 1 in CA., the part near Kirk Creek is fun and beautiful.
The road into the canyons of Canyonlands NP from Island in the Sky is amazing, would I take my RV down there, no! But I figured out that one of the favorite 4X4 spots in the country isn't for RVs, even little ones like the Bounder, we took the Suzi and it was really cool.
There are not many but there are roads that were meant for foot traffic, I got on one of them when the BRP was closed due to snow. I guess we were young and stupid way back in 2011 and while we really didn't know how to get out of there, but we had a fun four hour out of the way side trip and maybe the brakes got a little warm, but, now that were older, I'm 75, as I look back, we were never in danger.
I am not deriding anyone who has fears, concerns or doesn't want to exceed there personal capabilities, I am saying I think that there is a lot of overthinking about routes and eliminating anything but a smooth level straight road when planning on getting from point A to point B.
One of us here has a tag line that says "Options you've got to have options". Mine is and always will be, unhitch, turn around, hitch up and go back a ways and find another route when the rig won't go any further or if I don't feel safe.
Remember the Corps of Discovery, no one knew the best route from the Eastern Frontier to the Pacific. Now we have so many choices, no one can definitively say which one is best.