Final Fantasy 16 doesn't have American voice acting because of angry Americans
gamesradar.com
gamesradar.com
If anyone played the Mark of the Assassin DLC for Dragon Age 2, you might recall how utterly out of place Felicia Day sounded in that game. It was like if Larry David showed up in the Fellowship of the Ring, but everyone else continued to play it completely straight.
Anyway yes, British accents in European settings are good (even though technically, if you go back far enough, Europeans accents sounded more like some parts of the American South now... it's all very confusing)
It would be weird if a game set in Medieval Spain had voice actors who simply sounded like Modern Mexicans. AFAIK, they have pretty big dialect differences.
As if middle English sounded closer to British English than American English.