I don't know that Brahmanical society suffered so much under Buddhism. Many of the most famous Buddhists from the various early schools were from Brahman families and the Buddha seemed to get on well with many of the Brahmans he coversed with as recorded in the Suttas.
By bramhanical society I meant not the people who were in search of truth (like sariputta / Moggalana/ kassapa) but those who earned their livelihood by conducting various rites and rituals etc. There are examples of such people having conflict with Buddha's teachings even during his lifetime, Buddha / some of his disciples were able to invoke a change of heart in many of them is a different matter. And please none of his students were 'Buddhists' Buddha never taught 'Buddhism' he taught 'dhamma' which is universal. On conflict with at least parts of bramhanical society, please reconcile this :
In order to delude the demons, he (Lord Buddha) was present in the form of a child on the way while the foolish Jina (a demon), imagined him to be his son. Later on, Lord Sri Hari (as avatara-buddha) expertly deluded Jina and other demons by his strong words of non-violence.By deluding the demons Buddha was able to get back the power to the devas. – Brahmanda Purana
` The delusion of the false teacher paused not with the conversion of the Daityas to the Jaina and Bauddha heresies, but with various erroneous tenets he prevailed upon them to apostatize, until the whole were led astray, and deserted the doctrines and observances inculculated bythe 3 Vedas. [The teacher was an illusory form of Vishnu, while the Daityas could not be destroyed whilst they performed the sacred rites adn were slain b the gods]'
-- [V.P. Bk III Ch XVIII p. 271]
At this time, reminded of the Kali Age, the god Vishnu became born as Gautama, the Shakyamuni, and taught the Buddhist dharma for ten years. Then Shuddodana ruled for twenty years, and Shakyasimha for twenty. At the first stage of the Kali Age, the path of the Vedas was destroyed and all men became Buddhists. Those who sought refuge with Vishnu were deluded.
- Bhavishya Purana
"tatah kalau sampravritte sammohaya sura-dvisham buddho namnañjana-sutah kikateshu bhavishyati
Then, in the beginning of Kali-yuga [he] will become the Buddha by name, the son of Anjana, in Bihar, for the purpose of confusing those who were enemies of the devas. - (srimad-bhagavatam 1.3.24)
Further Adi Shankaracharya was in no way kind towards Buddhism
The various Indian religious traditions were pretty adaptive and seemed to borrow from Buddhism pretty liberally. The Gīta seems to mostly continue with themes already developed in early Upaniśads.
the point being put to test by me here is very different i.e. whether Mahabharta /Gita was written prior to post Buddha's passing and latter seems to be the case.