Why didn't Musk apply for a patent?

It is a risk to apply for patent disclosure technology, and it is also a risk to be imitated and unable to defend rights without applying for a patent. Take the lesser of the two evils. If you have innovative technology, you will apply for a large number of patent protection with the general trend of the country. Musk thinks that the main competitor in the future is China, and the patent application will be copied by China, so it will be protected by technical secrets.