Everyone is receiving racism but it's the truly privileged that can do so and claim they aren't guilty of it themselves.
Unfortunately, U.S. discrimination laws have a long history of replacing perceived, hard to demonstrate/prove discrimination with actual explicit discrimination in the other direction... so although you may be morally correct, you're likely to be legally incorrect.
Caste exists. It didn’t need to, but people invented it. Pretending it isn’t real and doesn’t affect people’s lives is not how to fix this.
You're not describing reality since there is no such thing as a "lower-caste person". Stop thinking, talking, and acting as if there is.
You can't legislate your way out of it, you just stop doing it, including the language.
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.
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.
Instead of a law to stop "lower" and "upper" caste from discriminating against each other (like that comment was saying), the entire concept of caste needs to be purged.
That won't happen if you continue to use those very terms and then say it's (describing) reality. The sooner people stop dealing with it, the sooner it stops being a (real) thing.
Like, who is “we”? In any situation where one group has structural advantages over another, there are going to be people who are very much not on board with merging the groups. If your plan to equalize everyone is just “pretend the groups don’t exist”, it will fail, because you’re simply ignoring a status quo that others are actively working to preserve.
But if you want to refer to things in a really widespread system by their name, then you show respect to the people practicing the system and may have more success in saying — keep believing what you are believing, but in this context you cannot enforce it. You may have an easier time getting it adopted then.
In the case of the caste system, my initial reaction was like the sibling comment but then I realized that I personally (and many Indians today) no longer believe it has anything to do with reality and is in fact just a self perpetuating mass delusion. So the question is, do we therefore have a right to gaslight and disrespect the beliefs of those who do believe it if they come to live in our country. My guess is yes.