The view that Brahmanism contributed to Buddhism's downfall is BS ofcourse
But H-nationalists have encouraged this misconception by lionising the great Adi Shankara as the vanquisher of Buddhist arguments
Sankara's writings barely discuss Buddhism
An unfair criticism for sure
But that's something they wouldn't have said if the historical Shankara was primarily a "vanquisher of Buddhism"
This argument - I heard from friends, relatives, elders - none of whom were themselves Buddhists, or from the Left
Maybe because they liked the idea of Sankara as a great vanquisher of a rival sect
And now we are not happy
This is what happens when we are not rigorous - bad ideas / theories we may have embraced expediently in the past, come back to bite us
These snippets are not sufficient to regard Shankara as a "vanquisher of Buddhists"
"Sankara's brilliant intellectual power refuted the Jain and Buddhist doctrines which had then gained ground on all sides and established his own Non Dualistic doctrine"
Adi Sankara was no politician. He was primarily a philosopher, who came on the scene when Buddhism was already in decline
Also the "Non dualistic" doctrine predates Sankara
But he also critiqued other Vedantic schools like Sankhya, Purva Mimamsa
He also critiqued Bhagavata religion
But Bhagavata religion was not "vanquished". If anything it boomed in the centuries post Shankara
Such myths have been misinterpreted by neo-buddhists in our times, and is coming back to bite us