English is the defacto language of business and its the lingua franca for the world. Lingua franca is a language that is adopted as a common language between speakers whose native languages are different and so it’s how many people around the world talk to one another. Thanks to English Chinese and Indian businesses can get negotiate deals.
So having a good working knowledge of English is important for many people hoping to advance in their careers and it’s a measure of how well a country’s school system is adapting to global needs. If you can’t talk to someone, you can’t do business with them.
It’s no surprise that former British colonies do better as English has been institutionalized for longer. But it’s important to note that a good education program can help companies compete. In the end the ability to talk to other people from different cultures with different languages is critical for global business and diplomacy. And while Chinese and Spanish are more widely spoken languages, English remains the best choice to be able to talk to the world.