it was something akin to the protestant/catholic schism except the critique got reincorporated into the version of hinduism that was practiced at the time. it's why there are relatively few buddhists in India. led to some cool stuff philosophically like an atheist branch of hinduism and a lot of social reforms. of course it literally all got rolled back, especially after the British took over. so much was lost through colonialism that it's hard to find much info on the beliefs and practices people were experimenting with at the time. "learn Sanskrit so I can do some original research" has been on my todo list for decades.