Another casual observation: most people who seem to say "oh we can get rid of the need for human labor in the manufacturing industry easy peasy" don't seem to work in the manufacturing industry...
Does janitorial count? Pretty sure it does. I've been pestering my boss to let me build him a robot that could replace me since I began
You have to understand that a post modern economy is dependent on people being willing to surrender their wealth. Right now there are people on earth that earn millions of dollars that they just don't use because they don't really need anything more. So instead they invest it into something to bring in more money, to invest more. If you approached these people and said "We could solve world hunger, and you would maintain your quality of life, but we need your land so we can farm and mine and what not." they would tell you to fuck off you communist scum.
If the land is useful for that it's probably already being used. I think the problem will swing around the other way, where they'll want automation technology to increase the yield and value of their investments, and we might get lots and lots of very efficient mines and farms everywhere as land-owners struggle to keep up with disproportionate shifts in their actual value. Might end up being worse, but hey, at least we'll have lots of carrots.
You misunderstand. resources are finite which means there must be some mechanism for allocating them. So even with robots everywhere there has to be a limit to how many 200 story tall solid gold skyscrapers can be allocated per person. It's not really a matter of completely running out of resources, but a matter of how much is available at any given time and who gets what. Also how much to produce and where these products go, otherwise you'll have warehouse stocked to the brim with widgets nobody wants and robots still churning them out 24/7 which doesn't make much sense.
That last bit is kind of the point of manufacture-on-demand. We already
have warehouses stocked to the brim with widgets nobody wants, they're called Walmarts.