I created a route in Google MyMaps and exported to a KMZ. I then imported the KMZ into Google Earth Pro.
The reported distance in Google MyMaps and Google Earth Pro differ by approximately 2km, over a total distance of 2km over about 700km.
Can anyone advise which would be more accurate?
As a check, I also imported the KMZ into QGIS, and the distance matched the Google Earth Pro measurement.