A lot of countries are happy to accept immigrants from other civilized countries. If some are not, that's their choice, I will look into those who are open to accepting me. We can have freedom of movement without tons of other regulations. I can for example move to Thailand as many of my friends did even though Thailand isn't in any way of form part of centralized EU government. They will just be happy if I live, pay taxes and spend money there. There are laws that need to be set at global level but set of those is way smaller than EU legislature operates on.