1)Who're the 'Aryans'? Lets push asides the nazi related rhetorics: It's old origin is simply an ancient word for Iranians. Iran literally means 'land of the aryans'. The ancient Iranians, a fairer skin people managed to conquer a darker skin people, the aborigine dravidians (related to australoids,aborigines of Australia) of the Indus valley. A dharmic spiritual religion was establish to sanctify the racial superiority of the conquerors. Its certainly a major ancient racial conquest which Hitler tried to emulate.
link:Ancestral Dravidian languages in Indus Civilization: ultraconserved Dravidian tooth-word reveals deep linguistic ancestry and supports genetics | Humanities and Social Sciences Communications (nature.com)
2)The Mulatto Effect
Unlike the apartheid of S. Africa, the dharmic caste pyramid in the subcontinent lasts 1000s of years with the help of a religion; like it or not, race mixing always happen. Also, I read that to placate/reward the vanquished dravidian elite, some of them were later bestowed 'aryan'/brahmin status. Many Mulattos in murica want to be considered 'white', so after 1000s of years, the average non-dalit hindus want to be considered 'Aryan'
3)Conclusion
Can you imagine what would hindudstan become without that dharmic spiritual religion of hinduism ? As I said, hinduism is the only major civilisational pillar/cohesive force, considered all the internal division there.