Why are ppl using Grapevine and how is it different than Blind and Hush (which died off I guess)?

I'm new to Grapevine. I go to Blind as well. Is it like the Blind for India? What is the incentive to post office gossip here? Why would Grapevine have a better recall than Blind (more relatable data/gossip)? What needs and usecases is it trying to solve that are different than Blind, Glass door and Fishbowl?