I think the cost and work remains the same. What has change is efficiency. Previously people had to manually program byte after byte. Then came C and streamlined it, allowing faster development.
With python I can write a simple debugging UI server with a few lines.
There are frameworks that allow me to complete certain tasks in hours.
You do not need to program everything from scratch.
The more code, the faster everything gets, since the job is mostly done.
We are accelerating, but we still work 9 to 5 jobs.
C, Python, and frameworks don't generate all-new code for every task: you're taking advantage of stuff that's thoroughly tested. That simple debugging UI server is probably using some well-tested libraries, which you can reasonably trust to be bug-free (and which can be updated later to fix any bugs, without breaking your code that relies on them). With AI-generated code, this isn't the case.