I think it is not about reservations or benefits majorly, but rather about the symbols that the Upper Castes are reluctant to let go of, like using caste names

I think it is not about reservations or benefits majorly, but rather about the symbols that the Upper Castes are reluctant to let go of, like using caste names as surnames, and wearing of symbols, even the manner/affectations of speech, that they use to keep themselves distinct from the other Castes. And also the stigma the Upper castes, (often very subtle) exhibit towards the lower Castes. And also the fact the higher social strata comprising of top most government officials and industry executives still seems to be majorly drawn from the upper Castes. Sometimes I'm amazed at the skill some have to infer another persons caste, from the subtlest of hints/clues... As long as people keeping doing this, it is going to remain a problem.