Proficiency in reading and writing is clearly useful.
Proficiency in musical instrumemts is not necessarily useful by itself, but it's a path towards mastery of something hard that typically involves a lot of intentional practice. Having been able to master something hard once makes it easier to master other hard things, because you can reuse the learning skills. Music has a little bit of applied fractions and what not, too.
The same thing learning to learn journey happens with learning a second language. But also, learning a second language helps develop skills and understanding of your first language, and helps develop communication skills for situations where there's a limited mutual understandable vocabulary.
Some languages have market value too. Better communication with employers, customers, and suppliers is valuable.
Proficiency in musical instrumemts is not necessarily useful by itself, but it's a path towards mastery of something hard that typically involves a lot of intentional practice. Having been able to master something hard once makes it easier to master other hard things, because you can reuse the learning skills. Music has a little bit of applied fractions and what not, too.
The same thing learning to learn journey happens with learning a second language. But also, learning a second language helps develop skills and understanding of your first language, and helps develop communication skills for situations where there's a limited mutual understandable vocabulary.
Some languages have market value too. Better communication with employers, customers, and suppliers is valuable.