I've tried Magic Earth a handful of times, but each time I dumped it because it marked a street as closed or wrong-way, creating a circuitous detour. There's no such issue in OSM; it simply hallucinated something.
I was testing it so I knew where I was going, but I'm reluctant to rely on it when I really need nav. Have I been supremely unlucky?
I've never had a problem with magic earth, personally. They have a feature that allows users to report road closures, speed cameras, etc... What may be happening is that a user local to your area is falsely reporting things for one reason or another. Unfortunately, I'm not sure there is a whole lot to do about this. It might be worth contacting the company about it.
The user reported events don't directly affect routing AFAIK.
I share your experience though, no problems for me yet. Their FAQ
heavilymentions that you should contact them in case any of the data is wrong.