Have they not already completed many millions of miles in simulation, back in 2018?
To me, it looks like self-diving capabilities have reached a maxima. The resources poured into it have barely been needle movers in objective metrics.
Yeah, but videos aren't objective metrics. For me, an objective metric is "went $FOO miles in $BAR conditions without needing any intervention".
What would you consider an objective metric?
But who decides whether intervention was necessary? This is still too vague.
Irrelevant - until the car has actually gone without an intervention for whatever the median is for human drivers[1], we can't very well claim that it is safe for use.
[1] The average human driver goes hundreds of thousands of kilometers without crashing.