Because for similar reasons to those discussed in a recently posted article, https://defmacro.substack.com/p/parallel-tracks, management tries to suppress engineer wages.

If you're incredibly good, you might be able to negotiate 20-40% higher offer than the initial offer, but beyond that they'll just reject you and go with another candidate who might literally be worth millions of dollars less and be a ridiculously worse deal.

Engineering management is simply not operating according to standard economics textbook definitions of rationality. It feels more like cartel economics.