Thats interesting. I’ve heard the same about the UK. Here in Germany the regional accents go further into becoming whole dialects, people tend to keep them while learning a standard German in school. Strangely I’ve been told that in New Zealand the accents are getting stronger among young people. I dropped my Australian accent subconsciously when I moved to Europe years ago as it wasn’t practical and hard to be understood when speaking English with people, it appears sometimes after a few beers or when I’m with other Australians.