It will never ever be as cheap as as cron job and a shell script. There is a certain limit to how efficient using an LLM to do a job vs using an LLM to create a job is. There is a large distinction in compute and power resources between the two. Don't mistake one for the other.
If I can run 50,000 fixed tasks that cost me $0.834/hr but OpenAI is costing $37/hr and the automation takes 40x as long and can make TERRIBLE errors why the fuck would I not move to the deterministic system?
Because you'll be outcompeted by people who make the best of the nondeterministic system.