Technology

I'd say this is exactly where the LLMs problems with it comes from. For most of us outside of the US and even a lot of people there, it's exactly that - a caricature of a lower class black person. However for many people it's a legit dialect of English they speak every day.

I don't live in America either, but I went on a cruise once and there were many Americans, including a black American couple who were very obviously urban. By which I mean, the wife wore high heels and a tight jeweled mini-skirt on a sea-kayaking excursion...clearly signalling that she hadn't spent much time outside of a city.

Anyway, I was shocked when they spoke exactly like The Jeffersons, with all the exaggerated whooping, non-stop vernacular, and stage-like mannerisms. It was so over-the-top that I honestly thought they were play acting, but after chatting with them for a while I realized that was just how they were. They were very nice people and clearly having a great time.

Not to be confused with African-American Vernacular English.

Aave is what I'd say is more "the kind of language a stereotypical black character in a movie would use".

African-American Vernacular English[a] (AAVE)[b] is the variety of English natively spoken, particularly in urban communities, by most working- and middle-class African Americans and some Black Canadians.[4] Having its own unique grammatical, vocabulary and accent features, AAVE is employed by middle-class Black Americans as the more informal and casual end of a sociolinguistic continuum. However, in formal speaking contexts, speakers tend to switch to more standard English grammar and vocabulary, usually while retaining elements of the non-standard accent.[5][6] AAVE is widespread throughout the United States, but is not the native dialect of all African Americans, nor are all of its speakers African American.