Not even the Scotts can understand Glaswegian! They speak a non terrestrial gibberish in Glasgow. If you’re not from there don’t even try.
Before the WhuFlu I used to run into a lady, mid 30’s, from England. She had met her American husband while he was working in London. She was happy to now be living in the U.S. but had one complaint, her children are growing up with “beastly American accents.” She smiled when she said it and she is so pretty I just smiled myself and nodded.
She and I once talked about accents and she noticed the difference between the older generations of Virginians and the kids. She told me about the accents from the various parts of England. I hadn’t realized a country as small as England had regional accents.
Kentucky still holds onto it’s accent. The hills of North Carolina, western South Carolina, rural West Virginia, the western mountains of Virginia and various parts of the deep south are also holding their accents. Pretty much anywhere away from a big city and interstate highways is still doing okay. Pennsylvania still has some regional differences as well as Wisconsin.
I’ll say Bostonese, though not as bad as Glaswegian, is also one of those accents that is not only hard to decipher but hard on the ear. How can so many people talk through their noses and think YOU’RE the one who sounds funny?