When I had access to surveying equipment (a Trimble R10 with RTK and sub-centimeter(!) accuracy, basically delivering ground truth), I tested the accuracy of Google Maps: in the region where I tested it, the projection of the aerial image was off by more than 2 meters!!

Fortunately, the author points this out in the article.

Kinda related but there's a challenge out to use machine learning to improve GNSS accuracy using built-in sensor data. https://www.kaggle.com/google/android-smartphones-high-accur...

No imu or other sensor data in the datasets?