I think the best ideas come from people who have both domain knowledge and an understanding of what's possible. Computer science gives you the latter.

If I was going through university right now I'd want to double-major in computer science and something else.

I agree.

Domain expertise is good, but coupled with software knowledge is almost a superpower, when it comes to software projects.

I have seen projects that took 6 months when done by 1 expert + 1 engineer taking mere weeks when done by a single person who were good at both, in a competitor.