Musician. Ease of monetization is far greater here. And it's independent monetization, meaning your individual talent is weighted higher. Pick up a piece of string and fashion a Chinese violin or get some bucket drums and you are instantly a money making machine that can bring an audience to tears. I'm Already a musician, so I see the scalability here too . Your limit to earnings is the size of your audience, which can easily be scaled based on your talent.
Followed by programming. I already program. From my experience it's overated. There is diminishing returns to further study. It's diminishing returns cause your individual ability is inconsequential because most projects are based on a group effort of hundreds of programmers, over an extended time period. The last time a single programmer could singlehandedly change things with their programming mind was in the 80s when things were simpler. Furthermore, there is very little benefit to knowing every language, as opposed to being good at a handful because of how specialized they are.
Last is language. I put it last cause It's too general of a skillset. Not scalable. Not easily monitizable. Furthermore, it can easily be subbed out by just paying an interpreter or using these AI apps. And I'm saying this as a polyglot who already speaks 5 and a half languages.