Sounds like their disaster recovery plan was insufficient, intensified traffic jams in already congested areas because of "backlog", and is now being fixed to support the current scale.

The fact this backlog created issues indicates that it's perhaps Waymo that doesn't understand the complexity of running at that scale, because their systems got overwhelmed.

They probably do, they just don't give a shit. It's still the "move fast and break things" mindset. Internalize profits but externalize failures to be carried by the public. Will there be legal consequences for Waymo (i.e. fines?) for this? Probably not...