Idk, pedestrian navigation has been pretty decent for me so far. (There’s been one case of it showing a path in Tbilisi that would require me to jump from a 3 m wall, but it was exactly once.) I suppose it depends on which city you’re in and how well mapped it is on the OSM.

Where it’s lacking is POIs – there’s way more stuff on Google Maps, and if I’m looking for some place in particular, I usually go straight to Google, then copy the location over to CoMaps.¹ I then try to add it to OSM when I have the time. Still again, there’s no reviews or photos (in the app; OSM does support photo linking).

Public transit is another problem. It’s usually okay for metro (MRT/LRT/etc), but I wouldn’t trust it with buses just yet.

¹ – yes, there’s been another fork: https://en.wikipedia.org/wiki/CoMaps#History