Good luck with that

You still observe this as a pedestrian.
If you are on the highway, there is no diversion and choosing an other road for for tens of miles...
Don't compare this to Africa, compare it to the German for example.

The job of navigation is to get you where you need in the easiest/fastest way.
Too much detail on the screen extremely annoying.

Your job is to plan a trip before you embark on it. You can do it in great detail, and with iGO it is very easy to add intermediate points/modify route.