Manna is a short SciFi novel that you can read in a couple hours. It's the classic setup of portaying a doom scenario versus an utopia scenario.

The first part is the doom scenario, in which the narrator explains how the U.S. economy got taken over by robots. This part is very plausible, with the simple beginning assumption that it is not the low-wage work that gets automatised first, but middle management. Through innovations in the fast food industry, the management software "Manna" quickly makes low-skilled workers so efficient, that all middle-management gets replaced by it. Soon, all air travel gets automatised and when robot vision is finally good enough, all transportation and all general low-skilled work is also replaced. The giant out-of-work population is put in welfare homes out of sight, supervised (and being kept hidden) in the most efficient manner by robots. This development is explained in a very plausible manner and serves as an example of the perils of automisation in the name of profit-making. I often see people on the internet linking to this story when they want to make that point and now I finally read it.

The second part deals with the narrator being flown out of his welfare housing to Australia, where his dad had, years ago, bought him a place in a novel society, which was built with technology that is open-source, transparent and centered around human needs, not profit (everyone has the same budget of credits to spend, it is a zero-waste system run by robots). It deals less with a scenario how it developed. Instead, it spends almost all pages with descriptions of the coolest technologies which the author could think of.

An interesting thought experiment, but it is only the first part, which makes this little novel/essay really worth reading.