In my view the hard thing is sight-reading. With programming, if it takes one person twice as long as another, to read or write a program, at worst their productivity will be a bit lower. Or maybe higher. ;-) If you can't read music at tempo, then there are certain kinds of work that you can't do at all.

Granted, sight-reading skill is a matter of degree. I can read a jazz band gig, but would struggle with complex modern orchestral music. In musical styles that I'm familiar with, I can often make a good enough guess about what's next, that I only have to focus my attention on the dangerous bits. My attention often wanders away from the page.

I used to think that sight-reading was something that had to be learned, starting at an early age. I don't know if I still believe that, but I know that most adults who attempt to learn, find it to be prohibitive. This is one reason why it would be great to find an alternative. Even a piano with keys that light up.