It is a very subjective matter.
You might be motivated by a position that requires a certain language or by any personal circumstances,such as living in a certain country and needing to communicate with the natives in their mother tongue.
If there is no such necessity then learning languages will be still a choice you make among many other alternatives and skills that you would like to acquire in your life.
No matter how interesting ,useful or beneficial it is to learn languages, it will remain an individual choice. For some just mastering one foreign language that is useful for their work or an international commonly used language is more than enough to satisfy their goals in life, while they will be concentrating on achieving progress in completely different fields of expertise.
For some others learning languages could be a passion, a hobby and could have a very positive impact on their personal relationships.
It is really relative and one 'should' maybe learn one foreign language for a concrete practical reason, however learning several languages is not a 'must' and not necessarily and in all circumstances a 'bonus' !