I mean, the same geographic constraints are true of Australia, New Zealand and Canada but they don't have anything near the level of insularity.

I think this will remain a problem on any platform that includes enough Americans. The general public in America just seems unaware of anything outside America.

I think this stems from their education system, what they (don't) broadcast on mass-media and how normal and even laudable they consider fanatical nationalism to be (did you know they require children to swear devotion to the nation state every day at school!?).

In any case, I don't think this is a problem that any platform that wants to include Americans can avoid.