Keynes was a different thing - that we could cut working hours to 15 a week rather than never have to work again. I think that would be quite possible with a drop of living standards - you could do it today by moving somewhere cheap and doing some remote work. I think it didn't happen due to human nature. We both quite like doing something useful with our time and like increasing living standards.

I inherited some money and don't need to work, but do work on stuff because I like doing it. I imagine that's what things will be like post agi.