"Proof-of-Brain, has been proven a failure, at least in its ideal form. It is, however, better than just wasting power like PoW."
Proof-of-brain is not an alternative to proof of work, delegated proof of stake (DPoS) is.
I'm fully aware of that. However, Steem allots some of the token inflation to content creators and curators.
Proof-of-brain and content voting generally could be turned off entirely and the Steem blockchain would continue to run, apps which don't rely on the voting for rewards such as SteemMonsters and others would still be working fine, etc.
I know. I've actually been saying for quite some time that I wouldn't mind if PoB were discontinued at the base layer at some point but not any time soon (meaning a few years).
Proof-of-brain was one feature added to the Steem blockchain intended to help it attract users and grow. It worked to some extent but its effectiveness to date has been fairly limited.
It has made also made the stake distribution somewhat more decentralized. Even if it didn't add too much value otherwise in terms of driving traffic, it has furthered the decentralization of stake.