They're not "good enough" - they dont provide the same comfy UI/UX that google maps and organic maps does. And organic maps is offline, so literally no data harvesting.
Osmand is the best but it's complicated and has too many features for a casual maps user. It's UI is not that bad as others suggest. I have both installed cause organic maps doesn't support saving routes/tracks.
I have that too but i just use osmand cause it's more convenient to just create a route for bike. I use open tracks when I need to track my speed, distance, etc.
Honestly the osm ecosystem is really good. Best part is it's always getting better.