You’re assuming a extremely tight labor market, which may be true since about a year ago, but definitely has not been true for at least a decade before that.
Before the current tight labor market, if someone who was living paycheck to paycheck found themself unemployed, they took whatever job they could get. Maybe they apply for 10 jobs and only hear back from 1 for an interview. They have hungry children to feed and don’t have any money for groceries. The employer understands that most applicants are desperate for any job so can tack on any terms they want - such as a non-compete.
Before the current tight labor market, if someone who was living paycheck to paycheck found themself unemployed, they took whatever job they could get. Maybe they apply for 10 jobs and only hear back from 1 for an interview. They have hungry children to feed and don’t have any money for groceries. The employer understands that most applicants are desperate for any job so can tack on any terms they want - such as a non-compete.