No nation in human history has undergone brain drain has atrocious as the United Kingdom's. Over the past 100 years every single valuable member of their society moved to the United States. The entire island is slowly turning into a Baltic state level shithole.
They were in charge of the planet. Then they lost to the United States. Then Japan. Then China. Then Germany. Then India. Next France. And they'll just keep going down since the only capable people left are making it their life's work to exploit the people even poorer than them.