Without changing career path, no I don't think so. I'm mostly in web development. I can't think of any skill that would significantly up my salary.

Now learning stuff like AI, or Cyber Security could, but that's a very long process, and basically a change of careers. (I'm not against that, but wouldn't call that "easy")

I am also interested in answers, so let's assume the answer to this question is "no". In my case, in order to boost my pay, I need to move >=2 hours away, pretty much.