This is not the first time programmers became more efficient. We've had that happen before; usually because of new languages, tools, and other things that help

This is not the first time programmers became more efficient. We've had that happen before; usually because of new languages, tools, and other things that help people become more productive. AI is just another productivity enhancing tool. Some studies suggest that the lines of codes produced per time unit is more or less constant across different languages. What matters is what those lines do. If you are programming in assembly, it's going to take ages of very verbose programming to get anything done. Do the same in Haskell and you might reduce it to a couple of lines of code. Based on what happened in the past, we might expect programming work to outgrow the efficiency gains. That's what has happened every time there was a step change reduction in cost for producing software. The community of developers keeps expanding and isn't shrinking.