"A dialect is a language without an army and a navy."--Max Weinreich. That's why AAVE, which has its own distinct grammatical structure, is called a dialect. Same for Haitian Creole, Jamaican "English", Italian and German regional dialects. Norwegian, Danish and Swedish are more intelligible to each other than all the foregoing languages called dialects (Genovese, Napolitano, Bayerisch, Schwabisch...etc). That's because they have states, armies and navies.

The Franco regime disparaged the banned Basque and Catalan languages as "dialectos"; of what language they never said. In the former USSR the burden of language and code-switching was always borne by non-Russian nationalities. Language is a tool of empire-building.

All over the UK language and accent communicates social class instead of racial identity. High status high earners of working class origins often lose the accents they grew up in--sometimes artificially, sometimes not.