"usually by relying on immense government subsidies" makes one think that Boeing and GM failed to do the engineering work that SpaceX and Tesla had done because they were somehow barred from some kind of government subsidy.

But of course, the opposite is true: Being, Lockheed, GM, Ford, etc. enjoy a lot of help from the government (money and regulation) and use a bunch of dirty tactics against Musk's companies. And despite this, SpaceX and Tesla did things the incumbents were incapable of doing. In some cases things that were said to be impossible rather than just uneconomical.

I think at least the "usually" in your post is unwarranted.