I think a similarly important distinction is that in the U.S.A., the prestige accent, General American, is truly neutral territory that is is not a specific regional accent of any place, — it would be quite normal for even a homeless man to speak it, at any place throughout the U.S.A.,, which would not sound usual.

The U.K.'s relationship with Received Pronunciation is very different: it is the native regional accent of the rich elite of London, and consequently it would be quite unusual for a homeless man on the streets of Liverpool to speak it.

At the very least, General American is an accent that can be spoken without revealing anything of one's birthplace and social situation. A man speaking R.P. reveals his wealth and upbringing around London to a greater degree.

The Finnish situation, for comparison, is that the standard language is spoken by about no one informally, and is a practically constructed languages that was created by the government by combining the most conservative elements of all dialects. — it is the native language of no one, so it is even more neutral territory than G.A., yielding kno one an unfair advantage.