Hypothesis: the primary evolutionary drive for the development of the central nervous system is to allow organisms to coordinate activity with their allies, aka their tribe(s).
Bear in mind that even organisms without a CNS can coordinate activity in meaningful and essential ways, the collective behaviour of slime molds being an example.
So what does the CNS add? It’s a knowledge graph that interfaces with your web of trust.
Tapestry protocol = concept graph + grapevine
concept graph = knowledge graph
Grapevine = WoT
CG and Grapevine each designed with the other in mind.