And, at least in my case, the sign on bonus and number of RSU was calculated based on some long-term estimation of stock price done by Amazon. That wasn't only done for compensation purposes. Obviously, having started in 2014 that estimation worked out rather in favor of employees. You could even see the impact rising stock prices had on variable compensation in the Amazon reporting for, if memory serves well, 2016 and 2017. Being surprised by the huge valuation increase in the last years was rather expensive for Amazon.

Overall, I considered the Amazon approach fair. But then I never considered the sign on bonus nor RDIs as part of my everyday salary, for me it was rather a bonus to be put away to be used when absolutely necessary. Allowed me to boot strap since Oct. 2019. Unsuccessfully so but that has hardly anything to do with Amazon.