The problem, as ever, is game theory. All you need is ONE bad actor to spoil the entire effort. See the panama papers.
If one country has laws that allow billionaires to claim residence or establish a shell corporation and have lower or no income tax and these bastards will all jump at the chance and that tax money will slip through the fingers of everyone playing by the rules.
Laws are great. But what we need is real enforcement by agencies with real teeth. Ban shell corps. Tax overseas transfers aggressively. Treat white collar crime like a real crime with severe penalties.