I think now it is called SE or Standard English, and the idea is to have a uniform sound within different timbre. My speaking voice has been described as incredibly distinct. That said, when I read quizzes, people with English as a Second Language like me as I put the start and end in words

Yes, I think British vs American media companies had different goals. Brits wanted a uniform sound, Americans just wanted enough of certain accents removed (Northeast ones were okay to stay) to avoid awkwardness on casting but they didn't care too much about standardization.