It’s a tiny ass island yet whenever a British person hears another British person they’ll be like “Oi guvenor! I know exactly where in Merry-ol-England they are from! Clearly they’re from Bovinshire-upon-Weavilton!” And Bovinshire-upon-Weavilton is a town like 10 minutes away from where they live.
media tends to lump “the south” into a single, monolithic accent that always seems to be some affected-as-hell Texas twang (where they pronounce “onion” like it has a “g” in it), but IRL there is a lot of variability between low country, piedmont, Mississippi delta, and southern Appalachian.
that doesn’t even get into who uses what idioms.
mass media has a way of flattening regional differences.