In the future, when self-descriptive hypermedia web APIs have taken over the world, we probably won’t need to write out-of-band human-readable documentation anymore.
But we are not there yet.
We are getting to my favorite part: automated testing! I used to hate it before and then I had to work on a big legacy application, which luckily had tests. I was so happy to be able to refactor it without breaking anything that now, I simply love writing tests for my applications.