it doesn't seem like it actually uses blockchain? according to https://en.wikipedia.org/wiki/Proof_of_personhood, it's basically PGP WoT but hopefully actually usable?
"BrightID and IDChain itself use DAOs on IDChain for governance."
and:
"IDChain (IDChain.one) is a proof-of-authority blockchain where validators are democratically elected by BrightID-verified unique humans."
[0] https://brightid.gitbook.io/brightid/idchain/introduction