There are more examples. Pretty much every every successful company in the CPU design space was headed by engineers.
The point is that hard engineering companies used to be formed and headed by engineers, including most of the juggernauts of today.
So when the parent said
> And none of those companies so far have become industry titans that challenged their original company.
I feel like that's untrue. Just about every major company in the space was formed by engineers forming a new company after getting fed up with their job, creating a titan that challenged their original company.
You just proved GPS point. They said it happens 1-2 times a decade and you only provided 3 examples that spanned over 4-5 decades.