Valid answers are “never”, “soon” or “already have - decades ago”, depending on where you draw the boundaries on definitions of AI and programmer.
Because AI means something completely different every decade, and the modern programmer works at a different level every decade.
Soon: While a decent programmer can code at a level beyond the capabilities of LLM based generators (which I assume is AI in this context), some companies employ literal hordes of programmers that fail the simplest programming tasks, like the fizzbuzz test. Their output is to slowly cut and paste haphazard bits of code from StackOverflow, internet forums, and code found lying around the company, and make something that after several bounces off Quality Assurance and adjustments by senior developer review, pass. It’s not a stretch to see that it’s mostly a matter of turning current AI tech into streamlined products to take over these parts. Are these the average programmers? There are many of them, so it could be!
Already have - decades ago: An average programmer in the early 1950s spent a lot of time taking specific tasks like “this module needs this specific pattern of input and must produce this specific pattern of output” and painstakingly turning them into machine code. They would pen and paper out logic like LDA 10; JSR FFD2; RTC;, turn it into A9 10 20 D2 FF 60 by referencing the manual and storing this byte sequence in a punch card or directly into machine memory address C000. Programs were much larger than this of course, and the skill lied in doing it correctly and making optimizations to the program so it would run well. Assemblers took over parts of this work, compilers took over more of it, then optimizing compilers and high level languages took the work away completely. These tools fit the 1960 era definition of AI. Now all people had to do was write a prompt to the AI like void main() { while(true) println(“yes”); } and it would do the programmer job for you.
Never: Programmers will, as they always do, use this tool for everything it’s worth and work on a higher level to make bigger things faster. AI can write reams of mostly-working code? Programmers generate entire sections of mostly-working code and spend their time filtering, adjusting, completing and shaping it.