The other sources factor, is that anyone that aggregates data, is probably going to charge for the data.
The product is free to us, as we provide them with map edits, and traffic data, which then they can try to monetize.
Buy this data from another source, negates the "how can we pay for this" issue.
Yes there are government sources, but these are normally only freeways/highways, so don't give you any data for surface streets. And then would require programming interfaces for each one.