One problem with studies like this is they often lump a lot of people together. In the real world, a software developer with 10 years experience and no degree is going to be a ton better than a kid fresh out of college. When you’re hiring developers, experience counts much more than a degree. Most of what they teach in undergraduate CS programs isn’t even relevant to professional programming, anyway. It’s only at the master’s level where the courses start to get interesting.
How if you want to increase your salary, add specializations and certifications like Salesforce and AWS. The harder it is to find a candidate with a skill you need, the higher the salary will be.