Also, code is only a small piece and you still need to handle your hosting environment, permissions, deployment pipelines, etc. which LLMs / agentic workflows will never be able to handle IMO. Security would be a nightmare with teams putting all their faith into the LLM and not being able to audit anything themselves.
I don't doubt that some businesses will try this, but on paper it sounds like a money pit and you'd be better off just hiring a person.
Those devs aren't code monkeys and they get paid the same as anyone else working in this industry. In fact, I think a lot of the more ADHD type people on here would strongly prefer working on a new project every 6 months without needing to find a new employer every time. The contracts between the consultancy and client usually also include longer term support than the limited time the original dev spent on it.
I believe 1099 worker growth has been outpacing hiring for several years.
Would you prefer that they hire, string those people along, and then fire them? That's a pain in the ass for everyone.
A lot of businesses are the only users of their own software. They write and use software in-house in order to accomplish business tasks. If they could get rid of their engineers, they would, since then they'd only have to pay the other employees who use the software.
They're much less likely to get rid of the user employees because those folks don't command engineer salaries.