Well there’s a huge variety of different accents in England, even more if you include the whole UK. British people themselves can struggle understanding other Brits from just 100 or 200 miles down the road. I say that as a Brit - I’ve worked in call centres where there would frequently be Liverpudlians, Geordies, Cornish etc calling back in a rage after being hung up on multiple times by colleagues who couldn’t understand them.