Photographer Nigel Danson described in this video why he has stayed with Nikon cameras for over twenty years. It wasn’t because Nikon is far better than any other camera system out there but rather once you start with one system it is easier to stay with one than to learn a new one.
Your mother tongue is kind of like picking up a camera system – you use it for the rest of your life. Why switch to another system of the one you’re using now when it does the job? Danson rightly points out that a camera is a tool to get the job of taking photos done. Language is also the same. Language is a tool, a means to an end. The end here is communication.
Unless you’re like me moving to a new country with a completely different language for communication then it isn’t necessary to learn a new language. Language learning is resource intensive. Unless you are learning another language for the specific purpose of training your mind for flexibility rather than for practical reasons then it might not be worth all that effort.