Yes, now you are getting into the concept of vicious/virtuous circles. People don’t move to places where no one wants to stay. They don’t stay in a place where no one would want to move to.
The problem is that it is very difficult, if not impossible, not enforce a steady population state. And even if you could, the economy still has to grow to at least some level where most people are able to enjoy some acceptable standard of living.
Note that your link only refers to a “steady state” in terms of resource consumption. There is no reason why you wouldn’t want your knowledge based economy to continue growing indefinitely. And indeed it is theoretically possible through the use of technology to continue growing real output without increasing your resource consumption.
Yeah, I can’t envision anything like this working without radical changes in social structure and individual psychology. It’s the stuff of wildly speculative science fiction, often dystopian.
The only “steady state” model we have is of hunter gatherers with access to particularly abundant resources. There the population is constant only because the mortality rate is so high, and the population is small enough to rely on renewable resources.
Even in those sorts of cases, the population (and the “economy” of stone-age societies) is typically going through cycles of growth and collapse. Throughout history and evolution, humans have just been able to sustain the growth and avoid declines through sheer cleverness. I don’t think it can last forever…
It is certainly possible to imagine that in the future we won’t have increasing resource extraction but rather decreasing resource extraction. One possibility is that if you’ve already mined 500 million tons of steel there’s not much need for new steel, you just reuse and repurpose already mined steel.
But even in a future society where there’s no growth in resource extraction you can still have economic growth by increasing intellectual property. Someone who comes up with a way to manufacture a widget using 10% less plastic causes as much economic growth as someone who figures out a way to produce 10% more plastic. Creating a new book doesn’t require more resource inputs, especially once the technology for e-readers mobile computing becomes mature. Using resources more efficiently causes economic growth.
Of course resource extraction from the Earth can’t grow forever. But there’s no reason we can’t have a global economy thousands of times larger than our current one.