If you think that "humans will be living on Mars and O'Neill cylinders 30 years from now", then you probably haven't tried to calculate whether that's actually economically feasible and whether it's practical to get to Mars and live there:
And that's only the cost to put an O'Neil Cylinder in Low-Earth Orbit. If we had to send an O'Neil Cylinder to Mars (or something that's comparable for sustaining human life), then the costs for space travel get exponentially worse than that due to the Tsiolkovsky Rocket Equation.
For more information, I recommend reading Futurist Fantasies by T. K. Van Allen. The book packs an impressive amount of information into just 100 pages.
in which case the fundamental Georgist argument of "you can't make more land" isn't true.
It is true. You can't make more land. Humans still must obey the laws of physics, whether we like it or not. Both the Moon and Mars are absolutely horrible places for any human to live, so humanity has nothing to gain from trying to live outside the Earth.
Now, I already showed my calculations for why I believe it's far too expensive to try that. I didn't even go over all the physical challenges that would make it virtually impossible. My judgment is that space colonization won't be possible for several decades, possibly longer, and probably never. It will probably take many people and many LessWrongers a while to reach similar conclusions.
In the 1960s, people thought that Humanity would've achieved the technological advancements in 2001: A Space Odyssey two decades ago, and that still hasn't happen by now. People need to recognize that technological process has clearly slowed down, and we've nearly reached its limits.
Another misconception that's worth clarifying is that the value of land matters more than the supply of land. There's obvious reasons why lots in Manhattan are worth more than acres in the Sahara Desert.
It seems like you can get 90% of the benefit of Georgism just by going full YIMBY and you don't have to wait 30 years to do it.
No, that's a huge oversimplification, and it's much more complicated than that. Any society would have to wait at least a few decades to transition to Georgism, but then the benefits will become progressive and compounding. I recommend reading Georgism Crash Course for a concise introduction.
If it will take at least 30 years to transition to Georgism because otherwise we screw over most people who have >50% of their net worth invested in their homes, then why bother?
Because we live in reality, not a sci-fi fantasy world where humans are invincible.
Even if humans could live on Mars, why would anyone want to live on Mars when you can live on Earth instead? Even Antarctica is a thousand times better than Mars. I will never understand why people fantasize about colonizing Mars when humans haven't even colonized Antarctica.
Henry George’s 1879 book Progress & Poverty was the second best-selling book in the entire world during the 1880s and 1890s, outsold by only the Bible. Nobody knows exactly how many copies it sold during those two decades since nobody was keeping track, but it definitely sold at least several millions of copies for sure. The Progressive Era is literally named after the book itself.
Georgism used to have millions of followers, and many of them were very famous people. When Henry George died in 1897 (just a few days before the election for New York City mayor), an estimated 100,000 people attended this funeral.
The mid-20th century labor economist and journalist George Soule wrote that George was “By far the most famous American economic writer,” and “author of a book which probably had a larger world-wide circulation than any other work on economics ever written.”
Few people know it, but the board game Monopoly and its predecessor The Landlord’s Game were actually created to promote the economic theories of Henry George, as noted in the second introduction paragraph of the Wikipedia article on board game Monopoly. The board games intend to show that economies that eliminate rent-seeking are better than ones that don’t.
So if Georgism used to have millions of supporters and solid economic reasoning, why did it never catch on and how did it lose its popularity over the past century?
(see the rest of the post in the link)