OSM is great for walking and cycling because pedestrians and cyclist are flexible enough to make small detours to map missing paths. In cities it's usually good enough if your destination is in the right spot, you can navigate by walking generally in the right direction. Finding potential shortcuts and getting to map terra incognita is just an added bonus.

And while I really like OSM I must say Apple got it right. The "report an issue" interface on iOS Map is easy to use on the go and requests are actually assigned to people who fix the map. I’ve signaled a few mistake and they all have been corrected.