The sociological factor underlying this fragmentation is the ubiquitous importance of caste networks. For getting a government job, access to credit, accessing development resources, dealing with criminal groups, and even to successfully migrate (as economists have shown) — caste networks matter. The key point is that these networks operate at the level of individual castes and are built around caste leader politicians. There is no OBC network, there is a Yadav and a Kurmi network. There is no Dalit network — but there is a Paswan and a Chamar network. There is no EBC network — but there is a Kanu and a Teli network.
As the process of lower caste empowerment has moved "downwards," from the upper castes to the upper backwards and now to lower backwards and Dalits, it is inevitable that historically marginalised castes will not be content to be part of an alliance that does not generate influential leaders from their specific caste and the networks that come with that.