This is a question which only you can answer. Learning a second (or third or fourth...) language will certainly always be useful in some way, but perhaps you don't aspire to a job that requires fluency in English. English is pretty much the official international language of trade and aviation, but not everyone ends up working at a company with international contacts/customers.
You might decide that you want to learn English so that you can better understand some of your favorite international movies or TV shows. There are a lot of folks who learn a second language just because it's interesting. I studied both French and Spanish while in high school. Several years later, I got a clerical job in the office of a small steel company. One of the company's customers was Volkswagen of Mexico, and when VW representatives would call our office and I answered the phone, I'd chat a little bit in my limited Spanish with them before transferring the call. Surprisingly, many of the VW executives complimented my boss on hiring a bi-lingual speaker (I was hardly fluent in Spanish, but apparently I was one of the few suppliers they dealt with who spoke a bit of their language. --This was in the mid-1980s, before there was a major influx of Spanish-speakers into the Midwest.--) So, anyway, by virtue of my limited knowledge of a second language I was promoted to a sales position and eventually took many company-sponsored trips to Puebla, Mexico, to meet with our customers.
I guess the point of my long story is that sometimes knowing a second language will have unexpected benefits.
Student or Learner