>> Listen to any streaming BBC service and marvel at the way different announcers talk <<
In the last decade or so, the BBC apparently has made a deliberate effort to have announcers with different regional accents — Scots, Irish, Canadian, Indo-Pak, West African, etc. But in earlier years, all announcers had to have virtually perfect RP.
(I don’t recall hearing an announcer or news reader, however, with an Australian accent. Guess that would be a bridge too far!)
My Brit in-laws are always amused when they hear people from their part of England, East Anglia, speak with what they call the the posh or received pronunciation accent. They wonder where they learned it. Some English accents are hard to understand. I have a very hard time understanding by bro-in-law from Norwich. However, I have no problem understanding my wife or her sisters who are also from Norwich. Sex and schooling play a part in understandable pronunciation. As in the States, women on average are easier to understand than men. That is when they speak of course.
And BBC types and humorists like to make fun of internal regional accents as well, as in this bit of fun from the old
UK TV’s the Fast Show-—”We’re Cockneys!”