Hypothetically just some wild numbers: You work 2 years, demand and receive a 20% raise. They cut the highest-paid in the next round of layoffs. You are unemployed for 1 year holding out for that salary level again. Employers won't hire you because you only last 2 years at a job, and haven't worked for 1 year. Your savings run out and you settle for a job working at 80% of your original salary.
Different regions have different values for the numbers above. Maybe on the west coast this can work in your favor. East coast is a little more conservative. Depends on the industry as well if longevity matters to the job role.