I don't think the concept of post scarcity is as ludicrous as wizards or alien handjobs,
but there seems to me to be at least as much faith as there is actual science behind the concept.
Baby steps. We already live in a world that would have been difficult for most people to imagine 100 years ago. Actually, I sometimes have conversations with people in which they claim that such-and-such technology "will never happen." Where such-and-such technology has already been around for years.
As for post-scarcity more specifically, I'll point out that it already exists in
some specific cases. Most obvious example: air. We don't buy or sell air. If you want some, it's available. Yes, there is a finite amount. But like above...pointing out there there's not an infinite volume of air, or that there isn't air on the moon...is missing the point. Air is not scarce in any practical sense.
But there are other things that
because of human action have
become effectively post-scarce.
Encyclopedic information, for example. When I was a kid, some people owned 26-volume encyclopedia sets that weighted more than I did. Now, everyone has billions of 26-volume sets worth of information available online, for free. Even if you don't own a computer, libraries provide free web access. This information is effectively abundant. Lots of things exist in effectively post-scarce abundance. Youtube videos, cat pictures, music, email.
Actually, now that I think about it, one of the more amazing things is video conferencing. That was
science fiction when I was kid. It was a thing we saw in
movies. That was what Darth Vader did in a fantasy future sci-fi movie to talk to his magical mentor Emperor of the galaxy. Think about that. Now, teenagers use omegle to flash each other. Nobody pays for it. Fantasy futurist sci-fi technology is now freely available to anyone who wants it.
But the
webcam isn't. The computer isn't. The web access might be available for free, but the car to drive to the library to use theirs isn't.
That's the big jump we need to see.
Physical goods becoming "post-scarce" abundant. Or I suppose we could go the other route, and make people not physical. I'm not entirely sure which is more speculative