In life you usually want to be a master of one thing, but have knowledge of many other things to apply that mastery as widely as possible. Learning 10 languages at the 101 level can let you say "Hi, I'm a master of (whatever)" to many more people.
No, you want to be a master of 2 things: A human language, and something that everyone else on the planet isn’t also a master of. Mastering two things is hard. Mastering three things is near impossible. (Although If you naturally get multiple human languages, from parents from different linguistic backgrounds, for example, that’s great. And you might have a chance of mastering both. But one of them ought to be English.)
