[mytailorisrich]

England/the UK is also a bit of a special case with its strong class system. Your accent is important socially in that regard.

This is still the case today but was even more so and educated upper classes people were taught to speak 'properly'. That very posh accent you hear in old British films and old BBC footage is called "traditional received pronunciation(RP)" [1].

That being said, accent is a social marker almost everywhere. It certainly is one in France, including because the country is very centralised on Paris and regional accents are usually deemed 'inferior' (it's similar to England, tbh). These days in France the accent and way of speaking you want to avoid at all cost is "l'accent des cités", i.e. the accent of people, often of foreign descent, from the bad suburban areas.

[1] https://en.wikipedia.org/wiki/Received_Pronunciation