Quote the article: “Basically, everybody’s myth is wrong, even the indigenous groups’”. I never understood how one could try to argue one's "race superiority"

Quote the article: “Basically, everybody’s myth is wrong, even the indigenous groups’”. I never understood how one could try to argue one's "race superiority" by claiming one's blood to be pure. Especially in Europe where you have lots of migration and mingling even in recorded history. The Roman Empire was an early melting pot and the following Völkerwanderung added only to this mix.