Language is a funny thing, in ways that are at once frustrating and fascinating. It has just enough internal logic to function like a series of equations, but with so many exceptions and contextual twists that it's a fool's errand to try to "solve" it. This is because language, unlike math, isn't based on fundamental, universal properties of reality but on the needs and quirks of the cultures that use it. Language is about perception as much as anything, like the above video that features actress and regular Youtuber Amy Walker demonstrating a selection of English-language accents, none of which are real. See, those are all stage accents, the versions of actual regional patterns that are exaggerated so they can serve as shorthand in scripted entertainment. Real accents have a much stranger relationship with mass media.
In one of the more intriguing developments in language of the past century, mass media has done a lot to erase regional accents across the United States. This may have happened in other nations, but I can't speak to that myself. That said, I geek out just a little bit at the prospect of Spanish-speaking populations in different hemispheres homogenizing their accents unintentionally just by watching the same TV shows. The Internet has started to change language, too, though it's a bit too early to say how it affects speaking as opposed to writing. We all know how the Internet has changed writing, or at least we think we do. There's a romanticist myth that the people of the pre-Internet 20th century were somehow smarter, more polite and more literate than people today, but I think that's based on the false assumption arising from less exposure to the literacy (or lack thereof) of large sample groups. Simply, we read more from average people on the Internet than we did in print before the Internet, so we wrongly come to believe that the average person from the past was more proper than the average person of today.
Modern English: Good Day Sir!Old English: Godlif Daeg Leof!Future English: OMG LKE GD DAY BRO! LOL ROFL! :)