I mean Egyptians and Sumerians were some of the longest lasting dynasties and they were extremely regressive and exclusionary. They had a small wealthy elite and lots of poor subjects. Feudalism, humanity's most common and enduring economic system was built around inequity, privilege for the few and repression.

Assyrians were extremely successful and they would commit random murder of their subject population.

I guess you can hold a mirror to just modern civilization and say western civilization... If you forget the racism and sexism of the 20th century... Which leaves the current society and if you're saying the society you live in is the most enlightened and progressive well I mean that sounds like the definition of bias