Or another way of looking at it: just because digging a ditch became cheap and fast with the backhoe doesn't mean you can just dig a bunch of ditches and become rich.
The software engineers who like "digging ditches" are going to have a bad time in the new agentic engineering world, unfortunately.
Here "digging ditches" corresponds to somebody else figuring out the detailed requirements and specification and handing it to the engineer to transcribe into code.
That's what the coding agents replace. Thankfully for most engineers I've worked with that's only a small part of their overall jobs, albeit one of the most time consuming.