AI may reduce the cost of code production, but it raises the cost of ownership.

Not just the cost of ownership, but the cost of disposal. Removing parts becomes much harder if you have to look through a lot more pieces to determine how they connect to everything else and what still relies on them. Programmers sometimes forget that they aren't just adding and making new things all the time, but that their job also requires digging through multiple older layers to excise obsolete unneeded things.