Recently there was a debate on Twitter about whether the legacy of the Indo-Aryans, one of the most impactful descendants of the Sintastha culture, was positive, significant and worthy of admiration. More generally, what have the descendants of the Yamnaya culture of the Pontic steppe done for us?
This is a complicated question. I think for Indian Hindus who revere the Vedas and the Vedic people the question has some broader and deeper implications. As I am not an Indian Hindu, any strident opinion on this is above my pay grade.
But I will repeat something that the Indo-Europeanist J. P. Mallory told me a few years ago: the reason that archaeologists fixate on the graves of these people is that these are among the few materials remains that they left. They were an agro-pastoralist society, and their arrival in Northern Europe 5,000 years ago saw the end of the ancient Neolithic traditions of megalith building. I think it is fair to say that these barbarians ushered in a “dark age” for a millennium in Europe.
What about elsewhere? In what became Greece the arrival of the steppe populations resulted in a synthetic culture that to be candid initially aped their Minoan predecessors, producing a coarser and more militaristic society. In ancient Elam, the arrival of the ancient Iranians resulted in the co-option by what became the Persians of much of the culture of the people of that region. Finally, the debates about India are endless in terms of what the influences on the Indic culture are in terms of whether they are Aryan or non-Aryan.
The daughter Indo-European societies were often quite culturally creative, in particular, the early Greeks and Indians. But I think this owes more to the fact that Indo-Europeans encountered either complexity (Minoans) or the faded elements of complexity (IVC), assimilated them, and leveraged their economic base to produce complexity and creativity societies. In contrast, Indo-European populations that remained closer to the ancient lifestyle, like the Slavs of the early medieval period, were culturally simple.
That being said, a skein of common Indo-European linguistic and oral culture did span Greece and India. Their origins were clearly brutal and barbaric, but the southern Indo-Europeans quickly assimilated and acclimated.