> It is not pie in the sky
Define "pie in the sky", because you have described the utopia that every eco-socialist has been chasing for 100 years...
The problem that makes it infeasible isn't the math, or the technology, it's people. Communism would work beautifully... if everyone in the world was different.
Huh. I did not ask for communism, nor do I believe in it. I do believe that people need to be rewarded for their effort. Democratic socialism and social democracy are sufficiently different from communism. When people's basic survival needs are met, which is the goal, they can be more free to pursue entrepreneurial and creative endeavors, otherwise they stay stuck in a minimum-wage job as under the current system. In the decades to come, minimum wage jobs need to be replaced by AI anyway, even physical robotic AI. It doesn't make sense to do by hand what can be automated.
A system where the population's wealth disparity keeps getting worse is nothing to be proud of. There have been systems of government in history where the system's total wealth made everyone more equal while preserving the reward for effort.