Small startups need to be poaching ‘Big Boys’ employees, not the other way round. I see many boutique shops offering (nearly) the same pay, and poaching from FAANG+M (The M is Micro$oft)
If paying 250k+ for a developer is insane, then so is a company able to pay 250k+ without running huge losses. Those developers still make peanuts compared to what the stakeholders and executives do, despite these salaries. It's ignoring the elephant in the room which is fat profits being with a few companies, subsequently making it tougher to compete for anyone not born in wealth or able to get VC money to play with.
SV could both bankrupt dozens of companies outside SV, slash that 250k locally and up to ante globally if it had a mentality shift, in less than a few years. That's how insane the profits are.