I think, the best explanation can be Pierre Bourdieu’s theory of “Cultural Capital”. He has borrowed the concept from Marx Capital and hence represents any cultural aspect (education, intellect, style of speech, dress, and even physical appearance, et cetera) that helps social mobility. Language stands at the core of cultural capital and it really explains why, with the rise of each empire, the language of empire was adapted by other people. It really explains why founders of Pakistan adapted Urdu as a national language and English as official language. Urdu was the heritage of Muslim (Mughal) empire (glorious past) but English was the coinage of current empire.
It is interesting to note that, despite of very obvious influence of cultural capital on every segments of modern societies, Marxist movements of last century and even recent 99% movement were largely based on economic class divide. And that is because cultural capital are the products of economic and social capitals. By increasing digitalization of the social institutions, the influence of the cultural capital are deepening. Seeing the people of previous generation, even those who weren't able to read and write properly are struggling to catch up with basic technologies are an indication of a social urgency and the role that cultural capital is playing in it.