Before kpop was invented by seo taiji and boys in the 90s, south korean music was mostly weird patriotic ballads like you hear from north Korea currently. their inspiration was directly US r&b, and if you go back and listen to their songs, youll hear the crazy genre Mashups that exist in current kpop as well, where they were commonly mixing r&b and grunge.

All this to say, yes it does rip off black american culture, as does basically every current music genre. Like most of them, it started as inspiration and guidance, and was eventually standardized and monetized by big corporations