And it's not a simple issue. Free movement works well for people who are comfortably off, but tends to trash the economies of those left behind. I don't think FoM is a full solution.

The end state is the end of nation states, and especially competitive nation state economies. Not only would this create a multi-trillion dollar peace dividend which could be spent on original R&D and social investment of all kinds, it would also create a massive wealth equalisation, end many of the more obvious and pointless kinds of wealth speculation, and create a global wealth boom, as location became much less important than talent and imagination.