While knowing how to code does provide an advantage to solo developers in the form of custom scripts which provide flexibility, doing so requires time and effort just like any other discipline, and in my opinion doesn't provide anything more valuable to a game than any other custom made asset, be it art, sound, game design or balance.
As you mentioned there are options out there for people that don't know how to code, just as there are options for someone like me who doesn't know how to make art. It's all about give and take, finding your strengths and passions and putting whatever they may be into the game that you produce, while doing your best to cover for whatever parts you're less skilled at.
I'm also not a jam admin, just a programmer who's passionate about their work.