Yes, most dominant cultures on the planet currently and for the last several centuries have been European.
BUT NO, that does NOT mean that all European cultures are dominant cultures. Using "European" and/or "white" as a shorthand for "widely known, assumed, and dominant" is easy, and also wrong.
Ask the Saami. If you don't know who that is, ask the Lapps. Same group, and most people only know them by ethnic slur, not by actual name.
Mighty dominant culture, that.
There are more oppressed minorities in Europe than most people have ever heard of. Some of them have done their share of oppressing in recorded history. Some haven't. Just like non-European, non-white cultures elsewhere on the planet. (Pop quiz: the Chinese, oppressors or oppressed? As usual, the answer is both and neither and which "Chinese"? and when? and with regard to whom?)
"Whiteness" is relevant to some cultural situations -- I'm not saying that it isn't. But I am saying that it is not the only possible categorization of fair-skinned people that can be relevant, especially not to discussions of cultural dominance, subjugation, appropriation, etc. And that using "European" as shorthand for "dominant" is not really very accurate, so if you could please refrain from doing it, I would appreciate that very much.
ETA: Since this has been quoted elsewhere, to people who don't necessarily know me, let me add: I am not claiming not to be part of a locally dominant cultural/ethnic group myself. ScanAm woman in Minnesota! And as much as I have my Haugean disputes, I am officially a member of an ELCA church as well. So -- locally dominant ethnic group? Um, yah. You could say so. This does not make the Saami rights movement irrelevant or nonexistent or even, sadly, totally unique.