It is a real question, regional and generational dialects have always existed. It isn’t a ‘loss of standard’, simply changes in said dialects. Clear communication is always a challenge and has, throughout history, been one of the guideposts of those who successfully advance in society.
I believe what is different now is that with the mass distribution of media, we are exposed more to different regional and generational dialects and those often spread further than what would have been their isolated enclaves in the past.
I spent some time Northern England several years ago and in some areas of the South. There is English and there is what people speak. They understood me but I will be damned if I understood them, until the ear got tuned.
I disagree on the first. Between clarity and dialect, the concern is clarity. And this about dialect: some dialects sorely lack it because its culture is not nourished by excellence. Ebonics is not a standard of clear communication because it is unable to adequately address the fundamental problems of society. Using it that way would turn the subject into satire.
That should be “speech”.