> Nobody asks which varna or jati you are from, or no one even mentions these words at least in urban parts.
It matters 100% when it comes to renting places, dating, marriage, friendship, kitchen access and so on.
> We never had a discriminatory system in the first place, and the only thing that remains today is the damage done by our various colonizers.
There are two types of discriminations. One is the ethical one. For example if you believe in free speech like US first amendment as a good principle, from it follows the principle of right of association and not association. All the discriminations the caste grifters often cite as "oppression" are actually perfectly ethical and in line with values like free speech, right of association and individual liberty. For example discrimination in marriages, dating, renting, room sharing, offering access to private areas, sharing food everything is perfectly ethical and also socially useful.
The other form of discrimination where you discriminate on behalf of someone else who expects you not to discriminate is obviously unethical, harmful and against the principles I cited above. For example government reserving government jobs for certain castes, government forcing private institutions to reserve seats based on caste or Individual employee discriminating in hiring when their employer does not expect them to.
I agree with you that Indian people in general do not discriminate that much in latter harmful type of discriminations (unless law mandates such discrimination) with exception of politics. There is no evidence that TCS, Infosys, Ambanis, Tatas ever discriminating in employment either. There is no evidence that there is any economic boycott of any castes either. Caste structure for example encourages inter-caste trade.
The most discriminatory aspect of Indian life is politics. Ambedkar was precisely included by Nehru because of his caste. He was a political non-entity, Nehru used him for his personal agenda. Indian President Daurpadi Murmu is an affirmative action President who is President only because of her caste and otherwise have no other qualities that made her the first choice for that position.
> President Draupadi Murmu being from a ST does not make any effort to hide the fact.
She does it because it politically benefits her, the only reason why she is President is because she is ST.
There are plenty other examples for example Scindia royal family is Kunbi. They are tribals. So are Holkars. They are goat herders. You will rarely see them talking about their tribal identity. Daivadnya Brahmins aren't historically from the Brahmin tradition at all. They are Vaishyas, coming from goldsmith occupation, their wealth enabled them to upgrade themselves.
The British Census officers record this again and again. They note that how "Nayi" (Barbers) suddenly became "Nyayi Brahmins" (Brahmin in charge of dispensing ustice) as they acquired social capital.
British did their part in solidifying caste by accusing rebel groups such as Pindaris (Elite Special Forces of Marathas) as caste full of horrible ravaging criminals. But their impact on rest of the caste system is negligible.