That's unless the code produced in the future is much more complex than today's.

Sure, but it would be actively bad to make the code more complex simply because we have machinery that helps us deal with the complexity. A big part of how people assess the models' coding capability is whether they create needless, incidental complexity.

That's like saying it'd be actively bad to make the code more resource intensive simply because we have machinery that helps us deal with the extra requirements. And as we know as computers got more powerful code didn't get lighter. If it can, it will.

Assuming it’s all going to be vibe coded garbage, yeah it will be much more complex. Like a toddler writing a symphony.