[usrusr]

One is an ad medium, the other isn't.

But it really depends not only on the presentation theme but also on the data set itself and that varies by region. I'm sure that there are still places where the sources Google is buying are better than whatever is on OSM, just like there are regions where OSM is just so much more detailed than everybody else. And yet others, where OSM is generously fed by an entity that also supplies Google and all the others because they are not doing it for the map, they are doing it for the place.

[kqr]

The great thing about OSM is that if an area someone cares about is sparsely covered, that's a self-solving problem. There are parts of the world with great detail in OSM only because I happen to care about them.