*NOTE: USA FOCUSED TIP*

This is not as clean a relationship as the tip would suggest, of course, but here are some things to consider:
- It is a popular practice for organizations to hire managers from the outside. This instantly places workers with many years of experience in other orgs as managers above individuals with a similar amount of experience, just within the same organization.
- Organizations thrive on workers who become settled within a job. They do not have to invest in additional training and the capacity of these workers are much higher than less experienced people. So there they stay...
- Salary increases sometimes do not keep up with inflation. For example, inflation for 2022 in the USA was 6.5% (not a good year). That means that unless you were given a 6.5% raise then your earning are worth less than the previous year. This percentage compounds over time, so those who have been working the same job for 10 years could be shorted five or six figures worth of compensation because raises have not kept up with inflation. Also, there are other forces like cost of living (COLA) that increase each year that impact earnings. Said another way, they would be making more money if they renegotiated their salary to match the current market conditions.
- Organizations view external experience as more diverse than internal experience because employees will have to learn different processes/job tasks when transitioning between jobs and they have insight into the working of competitors.
- Those who change to other organizations get to renegotiate their salary. There new rate is based on their previous rate, the current salary market, and years of experience they have gathered since their last salary negotiation.
- Employees who change organizations have more experience with salary negotiations. They are just better prepared to talk about their compensation than internal workers who quietly agree to the salary listed within the contract.

General rule of thumb is you want to achieve a notable promotion, pay increase, or change to a new organization at least once every five years if you want to maximize compensation.

To be clear, high salary should not be the only consideration. Workplace fit, job fit, coworker relationships, job location, benefits, and other things should be in mind when considering a change. Just know that the longer you stay, the more likely it is that you are loosing out on earnings.

Aside...
One of my previous jobs was as a pay equity analyst. It was my job to analyze an organization's salary data and tell them, with statistical certainty, how badly they were discriminating against race/ethnic groups and/or women. It was a blast to look through company data and look for trends within industries, levels of managements, or specific jobs. I learned a lot about how USA companies go about compensating their workers. It was extremely discouraging what I and other analysis heard from HR departments regarding compensation practices, but that is a story for another day...