Also, everybody by default shares their location when using it, no? So they get live feedback on traffic relatively for free (till some lawsuit will ban it). I can see it often changing and recalculating as I drive, albeit with some lag.

I don't think you can estimate overall worth of Maps to Google directly and easily. Its still #1 driving solution I use, its not perfect in dense traffic in cities but otherwise OK and for free, plus their estimates are pretty accurate.