This would help businesses, but it would take a long time to pay off. Furthermore, just because a language is taught in schools doesn't mean people become competent at it. Schools don't give students the experience required to become confident in the use of the language. If you don't achieve that then people will prefer their native language solution instead.
That aside, there's a much bigger problem: sovereignty. How many Europeans would just accept a foreign language being made mandatory in their country? Eastern Europe still remembers Russification. We also have the example of French and its spread in France. I'm afraid that this kind of a rule would threaten the entire European Union project.
Netherlands, Sweden, and Norway are at the top with very high proficiency. France is 31st and is famously terrible at teaching English. Spain is 35th, Italy 36th. So it seems to be possible to have good English from school when done correctly.
> How many Europeans would just accept a foreign language being made mandatory in their country?
Yep, almost nobody would accept this, that's for sure. People in France are already angry toward Ursula von der Leyen because she didn't speak enough French during the recent State of the Union... I personally don't care that much about my own native language and would love to see English be used instead, but that's clearly not the way others see it.
That aside, there's a much bigger problem: sovereignty. How many Europeans would just accept a foreign language being made mandatory in their country? Eastern Europe still remembers Russification. We also have the example of French and its spread in France. I'm afraid that this kind of a rule would threaten the entire European Union project.