In October 2012 I was sitting on the ledge of a store in Oxford Street, London, watching the world go by. Literally. In 30' or less, you could experience a parade of people from all continents, more impressive than the Olympic Games parade (and w/o flags). I called it "Global Street".
With an immigration policy more open than the US and probably any other country in the world (feel free to e-mail me to correct me if you have data that another country was more open in its immigration policy, I am not aware of one), due to its EU membership and a liberal non EU immigration policy, the UK was for years the "new America" (what America used to be before Ellis Island closed down).
Now it is not anymore (you have been reading in the news why and also consult other posts if you haven't).
So what country is now going to be the heart of real globalization (because you cannot have globalization without free movement of the human capital too)? Any ideas? There is a market opportunity for a country to become that. It will draw investment and business too, like the UK did (and will lose now). Of course, English has to be part of the package, because English is the lingua franca and that makes it even more difficult for a country to implement (see eg Germany).
What Theresa May has done and is doing to the UK is sad but to be fair it is merely taking the UK out of the leadership position it had in true globalization. Immigration policies like the one Tories are cooking up (they started before the Brexit ref re non EU migration, a 35,000 threshold for employment for non EU economic migrants) are the norm in the world, sadly. And many countries have worse ones. We are nowhere close to true globalization. And even further due to the new UK.