If the accent is so important to you, play Dragon Age, Plenty of Dwarves and Qunari to give you as much American accent as you want. It's a medieval like setting - the British accents fits within that. And as much as I love him, I'm just glad to play a game and NOT run into Troy Baker - just saying

Haha yeah Troy does get around....
But why do you assume I want American accents? When I've literally listed a half-dozen other accents that would be fantastic to hear? The only one I've mentioned is Imoen (from BG 1 and BG 2) which is Mid-Western, and that was to demonstrate the diversity of voice acting in the games that spawned BG 3.
BG 1 and BG 2 were medieval settings as well. So was Neverwinter Nights and Icewind Dale. All set in the literal world of Faerun, which is where most of BG 3 is based (Avernus section excluded so far). Medieval does not = British. No doubt it has been heavily represented and *should* be heavily represented in the setting. But there's a difference between it happening often, and it being the *only* accent when you have a dozen+ races, some from other planes of existence (Githyanki for example).
Races and characters have tremendous visual diversity. What I'm asking for is audible diversity as well. Which was exactly what BG 1 and BG 2 had as well.