It's a variation of the maxim "Don't make the customer think", what you want them to do should be the default action and you want them to do without thinking.
For some people in Europe now, they think about whether the thing they are buying/subscribing to is in the US or owned by a US company in a way that simply didn't happen in the recent past.
And all foreign transactions were done with a USD intermediary until the USA started making countries and banks question whether that was a good idea.