When did the definition of "market rate" become "what the top 20% of engineers make"? The "if" in your second statement is a big one, because the majority of engineers can't just get a job at one of those companies.
Because — A lot of the time when you see a company complaining about how difficult it is to hire “good engineers”, when you look closer, what you’ll really see is manager(s) (in denial) who really want to hire top-20% engineers at bargain rates.