I wouldn't look as far as cultural dominance. If you're abroad and in an emergency, you're just going to dial the number you remember from your home country on autopilot, and there's no good reason not to support that if the number isn't already taken for something else.

Yes, sure. But I am talking about Europeans, not Americans, who know 911. I see kids here who are familiar with 911 just through American media, which is really the only source here for anyone to know the number.