The twist is every new hire will be getting paid significantly more than every person wtih 2 years at the company, if doing the same job. That's because of how Amazon pay works. The first two years you're paid mostly cash, based on your on target earnings (OTE) number. The following two years you're paid some cash, lots of stock, designed to add up to the same OTE. That means the person who joined when the stock was high has a really rough years 3 and 4 because they're getting not just 50% below what they hoped but 50% below the market rate and 50% below what a new hire would get. The RSUs at Amazon aren't so much a bonus as a core part of OTE.

What it means is skilled Amazon workers can jump ship and collect vastly more money in the open market because they're going to be paid well below the OTE for someone in their role. Including some new hire. If they leave and get hired back, instant huge raise.