Earlier quoted context omitted.
I'm skeptical of autonomy in three years myself, but embedded engineers are hardly a convincing authority on the subject.
Were you also skeptical about landing orbital rockets 5 years ago?
Rocket science is a matter of applied physics, with materials science thrown in, and a bit of very well understood and straightforward software engineering.
Autonomous driving is a matter of getting AI models functioning to a well enough degree. My understanding of how this is done is you try to find more and better data to throw at it and tweak the models to hopefully make it learn better until the point it seems to pass your tests, which are whatever you've been able to come up with that you can think to test.
It's like trying to throw a pitch over home plate, but in one case you have a pitching machine you can aim and dial in the speed, and in the other you have a living pitcher. Only that living pitcher is an Orangutan you're trying to train.
One of those is a lot more art than science, and as such, getting well understood and reproducible outcomes that don't fall apart at a fundamental level when you add one more variable is harder.