Technology does not fix human corruptibility.
Of course it doesn't, but that's not the goal here. The goal is to prevent extinction.
It's quite true about consensus algorithms not being good for everything. This is why I brought up the scope issue near the bottom. I know I didn't fully explain that part. But there will always be someone in control when it comes to the individual. Consensus wouldn't be part of that decision making process. Consensus wouldn't be part of ones decision making when it comes to ones own property. For instance, we wouldn't take a vote on whether everyone in our community should be entitled to 10% of what's in your wallet (government however does this quite regularly).
Quick reactions are required by individuals, but they are not required by large groups. The excuse typically given is that quick reaction would be needed sometime to avert disaster. This of course is a disaster probably instigated by another authority (such as war by another country). Eliminate that, and what kinds of disasters are left? Getting struck by an asteroid? Hurricanes, tornado's, etc are all things individuals can cope with quickly. We don't need a consensus for that.