I'm not sure if there will be exponential growth, but I also don't believe that it's entirely necessary. Some automation-relevant performance metrics, like "task-completion time horizon", appear to increase exponentially - but do they have to?

All you really need is for performance to keep increasing steadily at a good rate.

If the exponential growth tops out, and AI only gains a linear two days per year of "task-completion time horizon" once it does? It'll be able to complete a small scrum sprint autonomously by year 2035. Edging more and more into the "seasoned professional developer" territory with each passing year, little by little.