Why do cars in America have such big engines?

I’m currently living in between New York & Ireland and I happened to be looking at cars. More like lusting over them but anyway. In particular I was looking at the Volkswagen Golf and I noticed that in the US it’s sold with a 2.5 liter engine. In Ireland it’s sold with a variety of engine options ranging from 1.2–1.6 liters.

Now my question is why in the hell is the American version double the size? I get that we love our big fuel guzzling cars and you get more power generally out of a bigger engine. Nowadays though I would think Americans are looking for more fuel efficient cars. I know I am and seriously if I’m buying a Golf I’m not looking for a muscle car. In Ireland, drivers are taxed based on the size of their engine so I get that there’s an incentive for a smaller engine but what’s the benefit to the American customer in only offering a larger engine? I’d totally trade some power for an extra 10 or so mpg.