A great inspiration for some language learners is to be able to speak to a large number or wide range of people in more than one country. To that end, a language learner may want to know which languages (besides the obvious English, Spanish, and French) are the most widespread so that they can go to more than one country and be able to speak in L2 to the general population.
Hindi, for example, is spoken by hundreds of millions of people, but it is official only in India. Therefore, unless you seek out only the Hindi-speaking communities in various countries during your travels, then Hindi won't get you very far outside of India.
It would also be useful to know in your answer if the various spoken dialects are comprehensible to each other. For example, most of the Spanish dialects in the many Spanish-speaking countries are quite comprehensible to each other, but Moroccan Arabic will be hard to understand by an Iraqi Arabic speaker and vice versa.