I think for that to be practical you need a lot of robotic automation to raise the standard of living and reduce the need for humans to compete against each other just to survive so much. Otherwise what you're saying is pretty much what the UN is already trying to do, but with no where near enough resources to make it happen.

We need to lure the global population into such a plan, so we need something to lure them with and something like robotic automation lowering the cost of all commodities and labor is the most plan I can think up to help reduce greed and give people less reasons to fight each other constantly. Otherwise there is literal constant benefit to screwing each other over and the more desperate your situation the bigger the incentive. Kind of like when we imagine a world where food runs out and law and order falls rapidly with it. That's the kind of wild asset of humanity we are dealing with, so we need a way to stabilize their living conditions so they act more sane and predictable vs desperate and lawless as we commonly see anytime living conditions deteriorate.