There's a deeply frustrating infantilisation when something is localized in the same language. My kids and I love Bluey, an Australian show, but apparently the producers had to refuse to have it redone with US and UK accents to stop it happening. Never understood what the problem with having David Attenborough instead of Sigourney Weaver narrate Planet Earth was either.
I think there’s something about British narration of nature docs that makes them more relaxing and engaging for American audiences. Especially those who grew up in an era of Discovery Channel and PBS where the narration was usually British, or South African, or Australian, or in the Commonwealth-tinged flavor of English of that location. Perhaps it’s nostalgia.
I think it started with Pawn Stars and went downhill from there. MBAs saw $$$ and had no qualms about dumbing down their national audience and trashing the reputations of the channels in the process. American TV is unwatchable IMO.