Choosing a university degree to maximise your salary is a counter productive waste of opportunity. Become a generalist where command line foo is your super power, not your day job.

People hire to get stuff done. They have zero interest in your qualifications. They have every interest in your github repos. One cool project trumps your degree.

Employment offers plenty of scope to increase your salary. What it doesn't offer is much space (unless you work for decades to earn it) to study anything for the sake of it. That's your current opportunity: you can choose to study something for the sake of it, like Mathematics & Philosophy, History of Computing or Smart Geometry.

Don't put yourself in a box. Plenty of other people will be trying to do that for you.