You make some good points, but I want to nit pick one thing: 'post scarcity' is not a real thing, and basically never will be. When expensive things fall in price dramatically, we generally increase our consumption of them dramatically. But, efforts are still made to use it efficiently at the margins.

One example would be screws. Screws used to be very expensive at all levels (the materials, the labor input, etc.) but are now extremely abundant and cheap (at least 1000x cheaper, maybe 1000000x). But, as a mechanical engineer, I can tell you that we definitely still try to use them economically. We try to use fewer of them in designs, we try to standardize them, and choose ones that are less expensive.