you realize that the caste system that currently exists is completely different from what it was conceptualized as right? you most certainly want to read the conversation between yudhistra and nahusha that talks about caste https://vedabase.io/en/library/mbk/1/30/

I don't think we actually know who conceptualized the caste system. Even Manusmriti seems to be not as old as we thought before.

However, even in Mahabharatha there are examples of Karna and Ekalavya who despite having qualities (as Yudhishtira claims) of Kshathriya, they were rejected by the society as being lesser.

It is possible that caste system is an extension and crystallization of nepotism. Typically professions and trade secrets are handed down the families and it is conceivable this was codified at some point far in the past.

To claim that caste system has a more philosophical foundation would be a bit of a stretch in my point of view, especially when it has been throughout the history being used suppress.