What you said, is correct. My take on it is different though. Being jack of all trades but master of none isn’t good as you progress in your carrer. Being fluent in atleast one langugare is pretty important. Let me explain, the nature of problems we face in the corporate world change everyday and if we change our tools accordingly, its not feasible. As far as personal growth goes, yes learning different languages is important to open up opportunities. Good read though!