I disagree. Normal classism can be overcome to a much greater degree than Caste. An upper class person may have 4 working class grandparents. A person with 4 lower caste grandparents will never be an upper caste, just like someone with 4 black grandparents will not be seen as white.

The caste system has been enforced strictly enough to even have an imprint on the DNA:

https://www.thehindu.com/sci-tech/science/Caste-system-has-l...

In other words, casts differ from each other in ways that are similar to how Jews differ from other Europeans. And I would definitely label anti-Semitism as racism, even if it is usually difficult to identify a Jew by appearance.