Any ancient scripture which is perceived to be preaching bias against one of our own has no relevance today. The greatest strength of our religion is to accept the wrongs, debate and correct the wrong. It just shows that we are bound to a certain centuries old book like some are. We need to work our way to fix the discrimination against some, we need to impart knowledge to our kids from the books that preaches equality, not the ones that divides us. Dharmics has always done that and thats why we are so.different from Abrahamics!! We should maintain the same standards. I know my words with hurt some but all I am doing ia stating the facts.
Hindu scriptures do have relevance today as they did a few thousand years ago. Which is to establish dharma, teach right from wrong and guide human conduct. However in doing so, the Veda's are the primary source of knowledge and then comes the Sutras and the smriti comes last in the order of hierarchy and importance.
Even the Indian judiciary and criminal code of conduct is inspired by the Yajanavalkya smriti (due to british influence).
Social discrimination is different from discrimination on the basis of law. One cannot impose law to disrupt the social framework, however law can treat everyone equally in its own eyes.
Equality exist only in the soul, not in human traits, strength, character, behavior or integrity. For all practical matters humans are NOT equal, however the law can treat them as equal.
Let us not confuse the law with Natural reality or social reality.