I never understood this attitude, which IMO is most prevalent in speakers of Romance languages and adjacent languages. What's the point of learning new language

I never understood this attitude, which IMO is most prevalent in speakers of Romance languages and adjacent languages. What's the point of learning new languages if you're just gonna relearn 50 different varieties of Vulgar Latin. Is learning slightly different ways to conjugate and spell what is essentially the same word in a dozen different "languages" that interesting?