Writing code has always been cheap. Deciding what the logic should be, and being able to change course was the hard bit.

But that's the thing - changing course is suddenly no longer hard. We've already reached a state where I can have AI generate a decent set of tests from an existing codebase (or better yet, I'd already have them ahead of time), and to then do a massive refactoring or even a full rewrite while I get a good night's sleep. There is nothing "has always been" about this.