However, they require constant human monitoring and interventions from those humans every few miles to work properly - and it's not clear that the need for those interventions will be solved with more training data.

https://www.theverge.com/23948708/cruise-robotaxi-suspension...

That article is discussing Cruise. Since it was published, a Cruise car dragged a pedestrian 20 ft, it came out that they need remote intervention every few miles, the CEO resigned, and they stopped doing rides anywhere.

Waymo remains available to my knowledge.