As soon as Organic Maps can route better, I'll switch back to it for driving. Magic Earth is my current tool. For routing and traffic shaping, it's as good as Waze. The driving / routing map (for me) is better than Waze or Google maps. I desperately want Organic Maps or OSM to work better.
Organic maps is OK and will get you to where you need to be, but routing is odd. It'll sit you in the worst traffic and doesn't know about road closures etc.
If I remember correctly Magic Earth claims to get its traffic information from public sources, without using user's locations like google. So no, location data is not strictly necessary for that.
But somehow, someone tracking it's users, I can't imagine other way to get data like this. Maybe some carsharing service, company fleet management or something like that.
Organic Maps is nice, but working with GPX files is still very terrible. It has no direct way to import GPX files created on desktop, you can only open them from the disk, and they will look very strange, not like routes but like a bookmark. But as I see, Magic Earth has even worse capabilities for GPX.