Comment by AIPedant

IMO the most relevant point is that, even with all that data, Waymos are backed up by a large team of humans that can help guide the cars through "difficult" common-sense situations that AI is simply not capable of handling, both because artificial neural networks are very primitive and stupid compared to vertebrate brains, and because it is practically impossible to collect enough data for the dumb ANNs to learn from. Self-driving companies are very cagey about this.