And it doesn't stop at phones. I kid you not, the main benefit of upgrading my early 2009 Mac Pro GPU was having a fully functioning Google Maps experience again.
The telsa maps are based on google maps.
I heard there were two ways to speed up maps:
1) turn off traffic, which significantly slowed things down
2) switch from vector maps to satellite maps. Apparently the map tiles of the vector maps require costly rendering for display, but the satellite maps just required a blit.
#2 may also explain #1, I'll bet traffic requires rendering too.