This is not true. Google is collecting incredible levels of ground / lidar truthed imagery. In terms of then doing a generation function from imagery to 3D mode

This is not true. Google is collecting incredible levels of ground / lidar truthed imagery. In terms of then doing a generation function from imagery to 3D model (without lidar) they are going to be in a good spot if they want to be. This is the same approach they have taken in many many other areas - huge ground truthed datasets, then infer without the ground truth.