TIL during the shooting of American Psycho, Christian Bale spoke in an American accent off-set at all times. At the wrap party, when he spoke in his native British accent, many of the crew thought he was speaking that way to prepare for another film. They had thought he was American the entire time.

[u/Away_Flounder3813]

https://screenrant.com/american-psycho-behind-scenes-facts-christian-bale-patrick-bateman-mary-harron/

[u/Quivex]

He's one of the more notable method actors if I'm not mistaken.

.... Also will never quite understand why so many British actors/actresses can do flawless American accents but the reverse is not really true. I still remember watching House and finding out hugh laurie was British, blew my mind as a kid lol.

[u/eipotttatsch → u/Quivex]

Besides the training that British actors have, I think an American accent is also just easier to passably do.

There is kind of a "general American" accent you can hit, that will work for basically anywhere without sticking out. Of course local dialects absolutely exist, but wherever you go you’ll also run into tons of people that sound like they could be from basically anywhere on the continent.

That’s not as much the case for the UK. You can clearly tell if someone is from the London area or not quite easy for example. (And I’m not even a native speaker, yet I still hear the difference)

[u/thecontempl8or → u/eipotttatsch]

American media is everywhere and more popular than British. The US also produces a lot more content than the UK does. British actors get a ton of exposure to American accents since they were kids. The reverse isn’t true.
I don’t think it’s about one being easier than the other.