It's very hard if not impossible to do predictions over century timescales. How relevant are 1926 resource problems to today? If you wrote your comment in 1926 you would be talking about rubber, fertilizer, coal, wood or oil, and 4 out of those 5 are mostly solved today.
At those timescales, mining the moon or Jupiter for helium might be realistic, so the limits of earth are no longer upper bounds.
At those timescales, mining the moon or Jupiter for helium might be realistic, so the limits of earth are no longer upper bounds.