The monetary system is just tabulation..
taking away pen and paper won't stop people from eating .. and wanting more than they need..
You really want to solve humanity's problems.. Study physics and build a transcendence mechanism such that we may leave these silly quarrels of flesh..
That or a doomsday device to kill us all.. Either one would work..
Replicators, and anti-matter reactors.
The former to solve problem #1, the latter to solve both.
I realize that on the internet.. the default solution to all problems is startrek.. As much as i love the notion..
replicators and antimatter reactors are based on impossible payoff mechanisms.. they could not possibly occur within the same existence frame as those who need them..
That is to say.. By the time we actually have the ability to "build" those things.. We probably wouldn't need them, because our current problems would've been solved long ago.