Google doesn’t own most of their map data - they license it off other companies that have spent decades and billions of dollars collecting map data from all around the world.

So even if Google gives a project a “special deal” it’s still not going to be free. Open Street Map, on the other hand, is totally free. And in some ways it’s better than Google Maps — because it has millions of people contributing to the map. No commercial mapping company can come close to that.