The economy serves humans as the end users of goods and services. Even if an AI can learn to design a house that is more earthquake-proof than any human design of the same cost, the AI can't decorate the interior without understanding human psychology both at the general level of the average human and the specific level of the human who will be using the house.

I didn't realize how much happier I was when I worked next to windows (as opposed to working in the interior of a room) until I was in my mid twenties. How would an AI know to tell me to design my home office with a big window when I didn't even know that was necessary myself?

The AI couldn't have learned from me (since I didn't consciously know that), and the AI couldn't have learned that sitting next to windows generated happiness for itself either. That means some other human being would be necessary to input that as a design constraint into the AI's architecture program.

The inability of AI to experience human feelings for itself means it will have to rely on humans to help it provide economic goods and services that are maximally useful. That means there will be a role for humans in the economy for quite a long time (possibly forever).