PoW is not invulnerable, either. The more decentralized the consensus mechanism (stake in DPoS or PoS or hashing power in PoW), the more secure the chain.

When it comes to blockchain governance or community governance, it's best if leaders emerge on a case-by-case basis having clearly defined and limited powers (not witness voting) delegated to them. @ocdb is a great example of how that works. It has been run by trusted and trustworthy individuals. But trust is not even as critical as it is in politics because any Steem Power delegated to them can be taken away at a moment's notice.

I'm very averse to people having authority over others other than in clearly defined situational roles with enforced consequences for abuse. Deep down, humans are stupid hairless apes ultimately controlled by animal drives. Most of us have internalized a conventional every day morality from the culture we've grown up in. That, too, is ultimately prevented from being broken down by the justice system - or in the blockchain world - hard coded blockchain consensus and governance rules. If either type of fundamental order should break down, the morally weakest would start cheating first, resulting in a cascade where everything would eventually break down.