The problem with this thought process is the same reason systemic racism is often brought up (Which I don’t entirely agree with, but there is probably an element of truth to it). Most people are not going to openly admit to being discriminatory. And they might not even be self aware enough to realize they are being discriminatory. So it’s not even a thing of explicit bias but your coworkers could be making decisions subconsciously because they perceive a caste a certain way.

While I agree with the point of your message, I don't think your personal experience and relationships with Indian is a good argument.

There are many stories of employees or managers that could not believe that their sweet quiet coworker bullied other coworkers of a different cast for months or years. People are complex and sometimes end up doing stuff we never thought they would be capable of. That's also probably why this is such a hard problem to fix.

A lot of Americans say this and don’t realize their Indian coworkers all belong to the same couple groups and that it’s actually pretty insular