That's likely the reason for the skew. They are trying to retain engineers past the typical time on site.

The problem with that is that they become a talent pipeline for Facebook/Google/Apple/Netflix.

I met tons of people who did 2 years at amazon and departed to Facebook for a fat offer that was worth far more than the remaining unvested amazon stock.

Trying to nickle and dime people when they come in the door just leads to people departing early. Employee turnover is a massive cost.

I have also met people who shifted opposite direction. The market for salaries in the tech space will self correct over time. If you are a solid engineer you'll get paid enough and it becomes more of a decision about where you want to spend your time. Do you want to move Facebook forward? Is there a new team in Google you want to work for? Is your passion movies so you want to work for Netflix?

At some point it is less about money and more about where you want to spend your time.

I can never grasp why any developer who didn't need the money would do anything other than work to build their own business. I know if I ever have enough to not worry about it I'll never work as an employee again.

There are more solid engineers than slots at those companies.