Earlier quoted context omitted.
This is not true at all. A lot of people In BigTech companies boast of passing a tough interview as their biggest accomplishment and beyond that haven’t really done much. Meanwhile, good startup engineers are used to learning new technologies quick, can work across the full stack, can own all aspects of their app/feature, work without much direction, never mind a formal spec, and generally are used to solve problems…
You've compared the worst big tech engineers with the best startup engineers. Those are rarely the choices faced.
This is from my experience as a hiring manager who has worked at multiple startups and now works for a large public tech company.