IMHO they should be inventing cars, planes and trains.
Why? Because they write code using tools made to accommodate people and when you are taking out people from the loop keeping those is useless. It's especially evident when those AI tools import bazillion of libraries that exist only to help humans tot reinventing and spending time solved problems and provide comfort when coding.
The AI programming tools are not like humans, they shouldn't be using tools made for humans and instead solve the tasks directly. IE, if you are making a web UI the AI tool doesn't have to import tons of libraries to center a div and make it pretty. It should be able to directly write the code that centers that and humans probably shouldn't be looking at the code at all.