I have been listening to a very interesting radio programme on polyglots at https://www.bbc.co.uk/sounds/play/w3csz4pt
There are interesting points about the ways that knowledge of languages brings power (reference is made to Mandela learning Afrikaans, which was seen as the language of his oppressors but that it was much more useful for him to know it than not know it). This seems to have resonance with the need for English speakers to know other languages.
A speaker explains how the knowledge of several languages helps her to gain respect. It also helps her to break down stereotypes.