Deep learning is great for a few narrow cases but there is no path to general human-like intelligence required for a complex human-like activity like self-driving which has an infinitely long tail of edge cases you can't train for with these large and "dumb" ML models equivalent to curve fitting.
The mistake of Tesla is betting on covering more and more of these edge cases incrementally but what's needed is qualitative change rather than incremental improvement.
By qualitative change I mean actual model of human-like intelligence, including reasoning and "common sense", which is a prerequisite for self-driving. The solution to this problem requires more than the sum of its parts.
It's kind of like planning to build an airplane before figuring out Newton' basic laws of physics.
I'm not sure that is possible on roads.
The fact that it tends to be in businesses that are among the most mature and hardest to get into is really amazing.
All of Elon's companies are heavily subsidized by US tax payers (energy credits for Tesla and solar, rockets are paid for by NASA, military, etc...) So to use tax payer money you need to have the goodwill of the tax payers behind you. Its worth every penny to lie and bolster your image of doing cool shit so people don't mind their tax dollars continuing to go towards your cause. It's 100% PR. Without US tax payers none of these companies would still exist.