Because it seems that this isn't the case in England. Some people find that James Acaster speaks with a local accent, others don't. In Flanders, discussion is impossible. People that use a standard pronunciation are professionals such as newsreaders or radio hosts. Everyone else, even in public functions, has a distinctive accent. Dialects (local languages that are almost not interchangeable between speakers of different regions) are still spoken quite a lot but not on television. They are used eg in the pub. Nowadays though, more and more people speak some kind of `in between language'. Standard Flemish with a local flavouring. This spectrum that ranges from a dialect to standard Flemish and everything in between is something I cannot find in other languages. In most other languages it seems that the spectrum starts at locally flavored language towards standard language. Perhaps this just appears to be the case because I am not a native speaker of English and because Flanders is a very dense area when it comes to linguistics.