Exactly. It's a nightmare scenario: you're a well-performing, well-paid (but still underpaid) Amazon employee. You change jobs for much better pay... But then Amazon sues.

Typically, you'll lose your new job, and probably become untouchable by most other employers. You'll be forced to pay a small fortune for lawyers, and spend numerous days in court, with the outcome uncertain, possibly for years, all while you're likely unemployed.

Not a chance most people would like to take.