Learning majoritized languages and their standardized varieties gives you more access to economic or social power in the world, this is true.
I feel like i have heard and even tried learning languages to "gain" and "open doors". I am from an immigrant family and nothing can be done without a forwarding pourpus in my life and I kind-of didnt realize that learning a language could be not mainstream, not helping me "open doors" per say. I could learn a dying language and be content that I am just learning a language and not worrying about economic power i could get from it. I feel like that takes a lot of stress off of my mind and will hopefully make future learning easier.