So will it turn out that actually writing code was never the time sink in the first place?
That has always been my feeling. Once I really understand what I need to implement, the code is the easy part. Sure it takes some time, but it's not the majority. And for me, actually writing the code will often trigger some additional insight or awareness of edge cases that I hadn't considered.
"So will it turn out that actually writing code was never the time sink in the first place?"
Of course it wasn't! Do you think people can envision the right objects to produce all the time? Yeah.. we have a lot of Steve Jobs walking around lol.
As you say, there's 'other stuff' that happens naturally during the production process that add value.