Salary is not just a salary. It also means you’ve learned and been approved of your work and your contributions to the company.
People always encourage others to work hard and say once you do that, you’ll get a relevant reward. However, that’s not true. It really depends on whether the boss like you or not. They always have thousands of reasons not giving you what you deserved. That’s why many people prefer to work for government as it’s in a relative fair way of the wage.