I think a large part of it is that software engineering is barely _engineering_, in the traditional sense. And I do not mean that in a derogatory way, I have an EE degree, but write software all day long.

There are extremely few EE jobs available to be people with only undergrad degrees, and literally zero available to those without college degrees. This is a huge limit on the number of potential job applicants.

So you'd _think_ this would drive salaries up, but...

There's also just fewer companies doing EE work, where basically every company on earth does something with software at this point.

So there is a supply/demand component, but there just aren't that many places people who want to do EE can actually work. If you're top-of-the-field in EE/low-level CE, you will be paid handsomely.