> And no, automation isn't a panacea either, because an economy not just requires workers to do work, but also people having money to buy things

Automation is the whole reason people have money to buy things. Before we had automation everyone lived on farms and sewed their own clothes. Only noblemen could afford to pay for clothes. Your intuition is plain wrong, I'm sorry.

AI may take away purpose if it takes away literally everyone's jobs. The wealth and productivity of the economy doesn't go away. It becomes more concentrated. De-concentrating it is a political problem.