From observation of where people are, where they hike and where emergencies tend to happen I suspect that most people could get along with a very simple compass.

If your into orienteering or geocaching you need the precision to find a small target in a large, often unmarked, area. If your life depends on finding a wet two foot hole in the middle of a desert you have to hit your mark within a couple of meters or die. But most people don't need anywhere near as much precision as that. If you can get within a stones throw of your target your golden.

Most people can get along without even considering declination. As long as they know which way is north, +/- 30 degrees, and stay inside obvious boundaries, like a road or river, you can find your camp and get home. Which is why a lot of sportsmen carry very basic compasses. Even a basic $8 button compass, as long as it is reliable, will give them all the information they need to orient themselves and avoid walking in circles.