Until the last couple of decades, most British movies/TV tended to use a lot of “Received Pronunciation” English (the Queen’s English) which has very crisp enunciation. Other accents were usually relegated to very specific character roles that highlighted the rustic “cockney” or “Yorkshire” character.
More recently, other British accents have been used more and many of them are the opposite of crisp enunciation. Some seem to be talking with marbles in their mouths. This seems to represent a greater democratization of the characters represented with less of an emphasis on upper classes.
This is by design to some degree over the last few decades for much of the UK television landscape too. Successive UK governments have directed the BBC (state run broadcaster responsible for huge amount of UK TV) to incorporate more regional content/actors/accents. Historically the BBC had often been accused of a London/“Received Pronunciation” bias.
This has been accomplished in a number of ways - opening more regional TV production studios, commissioning more content from regions outside London, hiring presenters/actors with regional accents etc, the net effect of all of which has been to broaden BBC talent pool beyond the usual cadre of “Received Pronunciation”-style presenters.
As one example, I personally find the presenter Freddie Flintoff to be almost impossible to understand on any BBC show he appears on, but he has exactly the sort of accent you would never have heard on BBC 40 years ago.
I'm well aware of the BBC shift in practice myself, understand many of the arguments for it, and yet ... if the end result is incomprehensible mush, well, They're Doing It Wrong.
I've cut back tremendously on my listening in part on this basis. (Overall quality of coverage also seems to have flagged, also often with an eye toward popularity over significance. I'm aware that there's been a war against the BBC by political elements within the UK, I disagree strongly with it, and feel that also has a large role in these trends.)
But as with online content: if your design and/or presentation are getting in the way of your message and ability to communicate ... please stop doing that.
In all seriousness, Baltimore has a pretty heavy accent, especially in the inner city & Dundalk. It's rather comical to say that they got English actors because they were more understandable, to then turn around and make them less understandable.
Given the extensiveness of the English vocabulary and me not being a native speaker, I appreciate visual media only using 3-5 different words. But movies are completely different from dialects that you encounter in the wild. Classical British actors are far easier to understand than other English speaking ones in my opinion.
The latest season of the Great British Baking Show/Bakeoff had a contestant that was very difficult to understand, both with pronunciation and slang (Lizzie). Ended up turning on subtitles just to more clearly understand what she meant. Love the broader spectrum of people they get on there though, not just Londoners.
Until the last couple of decades, most British movies/TV tended to use a lot of “Received Pronunciation” English (the Queen’s English) which has very crisp enunciation. Other accents were usually relegated to very specific character roles that highlighted the rustic “cockney” or “Yorkshire” character.
More recently, other British accents have been used more and many of them are the opposite of crisp enunciation. Some seem to be talking with marbles in their mouths. This seems to represent a greater democratization of the characters represented with less of an emphasis on upper classes.