Mastering several languages is very important because irrespective of the sector targeted by the job seeker; there will always be interlocutors speaking a different language (French or English)
Knowledge of languages may be one of the selection criteria for a job. For example, if you speak only one of the official languages, it would be difficult to be employed where bilingual employees. Moreover, bilingualism can be used as an elimination criterion. The same applies for holiday internships.
Holiday or professional internships prepare you for the future job and community life. Likewise, these internships enable you to gain experience.