It's funny how people who live in the UK (tho this is Irish) mock Americans for thinking they all have the same accent yet topics like this do the same thinking the yanks all have the same accent. Brooklyn (pre hipster) sounded different than most NYC people. NYC in general sounds different than Boston. Georgia Southern accent is vastly different than a Tennessee accent. Where I live we don't have an accent at all. There is no singular 'American Accent' at all.
This is true. It's funny actually, I got in a fight in the Youtube comments section(unprecedented and shocking, I know) because someone basicaly called Americans stupid for not knowing accents. They got pretty pissed that people didn't like the voice acting in Xenoblade 2. They literally said something as cringy as "You guys don't know any of our accents. Our dialect is literally alien to you, and yet I feel like I know all the american accents just from watching TV". The irony in that last part was way too strong.
Although to be fair it is kind of a well acknowledged fact that there are many accents in Europe as a whole.