I think some people are missing the point, especially Chaotic Good.
On the little island the current accents are coming from, there are plenty of accents, some wildly different from each other. Correct me if I'm wrong but I'm pretty sure Faerun is a lot bigger than England and as far as I know, no interdimensional aliens live in England. Everyone sounding more or less the same just doesn't make sense.

Pillars of Eternity 2 did this well. Not everyone liked all of the accents, myself included, but you had a real good idea where everyone was from based on their accent. Some characters even going so far as to use accents not their own, and you could comment on that. It adds a lot. As it is now, it's like everyone grew up very near each other and interacted with each other daily.