> The entire software development lifecycle was, it turns out, designed around the idea that it takes a day to produce a few hundred lines of code. And now it doesn’t.

No, it was never designed around that. All methodologies of software dev don't focus too much on writing the code, but on everything else: requirement definition, quality, maintenance, speed of integrating feature, scaling the work, ...

Personally with 20 years of experience, I never seen a single company were writing the code was a bottleneck