> knowing multiple languages from childhood

This is phrased ambiguously, but most Europeans only start learning foreign languages in school, so around age 6 or later. By that time you're past the "critical window" and you'll almost surely have a very recognizable accent and learning the language is very effortful and takes many years. It's still probably easier to learn when you're 7 than when you're 40, but it's not even close to language acquisition as a toddler.

You're also forgetting that school-based language instruction is not so great at all. Imagine a class of 30 students having a 45 minute English class twice a week, by a non-native teacher with a heavy accent. It's not a lot of learning, very little speaking, and most kids unsurprisingly don't learn to speak well from that. It's mostly about memorizing grammar tables and vocabulary for tests.

You need much more intensive paid courses or private instruction if you really want to be good at it, even as a teenager. Not strictly necessary but learning purely from public school is usually not as effective as you seem to think. Or you have to be an outlier in diligence and do a LOT of homework practice on your own, translating, reading, writing, listening to media etc. Video games can be a great motivator but it also gives a very lopsided skillset and won't easily get you to pass a B2 or C1 exam.

And yes, it's true. For Americans learning a foreign language is an exotic hobby or a requirement of some very rare foreign-associated jobs. For people whose native language isn't English, learning English is just part of the basics for professional work. It's around the same level in basicness as getting an undergrad degree. Certainly not something that every single person does, and there are jobs you can do without it, but white collar, professional knowledge work will require it.

In most European countries you also have to learn a second foreign language at school at some point, though not as many years as the first foreign language. This one is usually the language of a big nearby European country, so German, French, Italian or Spanish are popular. But just as it is for Americans, learning this second, non-English foreign language is much less motivating once you know English. Though economic motivations do exist, for example to learn German, especially when you live close to the DACH (Germany, Austria, Switzerland) countries and there are many economic ties.