It actually has a genetic basis. According to David Reich in his outstanding book Who we are and how we got here, the varna/jati castes and sub-castes have been able to maintain a level of endogamy stricter than Ashkenazi Jews for millennia and there is 2-3x more genetic distance between two different jati groups coexisting in the same village than between North and South Europeans.
So basically you had a group of invaders who came to India, proclaimed themselves both racially and morally superior, and enforced a rigid system of miscegeneation laws to prevent themselves from being diluted. Makes the wildest dreams of white supremacists tame in comparison.
Of course, none of that justifies the discrimination. I don't know how to fix it either, India tried but hasn't succeeded. B. R. Ambedkar, the author of India's Constitution came to the conclusion that Hinduism is unreformable and that former untouchables like himself should convert to Buddhism, but that hasn't happened on a large scale. Subhas Chandra Bose proposed to abolish the caste system through socialism and inter-caste marriages, but he was an authoritarian bordering on Fascist.
Your idea of abolishing the concept of caste system is noble, but it has been tried and failed in India. Just as you could say making people color-blind would solve racism (setting aside the problem of reparations for past injustice), but how do you make it happen? It's a social problem, and there are seldom simple solutions. Banning the language won't make it disappear, just as (effectively) banning the N-word hasn't made racism go away.
Genetic differences don’t mean it’s not made up. It’s not like we studied people’s genes and went “hm yes you can divide this ethnic group into four subgroups, Science!” People made a system where they divided themselves, and over time that division resulted in some small but noticeable amount of genetic divergence.
But there are, like, trillions of different genetic differences between all of us, and you could draw totally different lines around people and find a genetic basis if you really wanted. The genetic basis is used to justify the arbitrary groups; the groups are not an emergent phenomenon of the genetics.
You're confusing cause and effect. The genetics did not emerge from the castes, the castes were an effort to entrench through religion the superior social status of invaders who were a different group with distinct genetics. They were not imposed from within by a faction of a unified group that subsequently diverged.
So basically you had a group of invaders who came to India, proclaimed themselves both racially and morally superior, and enforced a rigid system of miscegeneation laws to prevent themselves from being diluted. Makes the wildest dreams of white supremacists tame in comparison.
Of course, none of that justifies the discrimination. I don't know how to fix it either, India tried but hasn't succeeded. B. R. Ambedkar, the author of India's Constitution came to the conclusion that Hinduism is unreformable and that former untouchables like himself should convert to Buddhism, but that hasn't happened on a large scale. Subhas Chandra Bose proposed to abolish the caste system through socialism and inter-caste marriages, but he was an authoritarian bordering on Fascist.
Your idea of abolishing the concept of caste system is noble, but it has been tried and failed in India. Just as you could say making people color-blind would solve racism (setting aside the problem of reparations for past injustice), but how do you make it happen? It's a social problem, and there are seldom simple solutions. Banning the language won't make it disappear, just as (effectively) banning the N-word hasn't made racism go away.