If Bitcoin had not been Proof Of Work, it wouldn't have been revolutionary, and the cryptocurrency industry would not have thrived or grown to the point it has today. Proof of Stake alternatives are able to exist largely in contrast to Bitcoin, rather than obsoleting it. Fundamentally, Proof of Stake is similar to the existing fiat system - the rich control the system, the rich are closer to the production of new coins, and thus the rich get richer.
Proof of Work has a number of critical advantages:
- Initial distribution: Proof of Work gave a mechanism for the initial supply of coins to be distributed anonymously, fairly, and without a central entity. Ethereum replicated this model, but most other Proof of Stake coins instead had an initial distribution that more resembles a pre-mine or centralised airdrop.
- Anonymous participation:
- Strong objectivity: An individual Proof Of Stake node cannot determine which of two potential chains are valid without reference to other peers. Offline transactions are not possible in an environment where sovereign determination cannot be conducted.
- Fork choice: ~~. See blow "Resistance to plutocratic capture".
- Physical scarcity: When
- Resistance to plutocratic capture: Although it would not be pleasant, a 51% mining attack on Bitcoin would not end the chain in perpetual submission. Among other defences, there is always the potential for more mining chip production and more hash rate to come online and claw back hash rate distribution or the development of new technologies allowing more efficient mining. It would also be very evident such an attack was ongoing. In contrast, Proof of Stake systems silently captured by a majority anonymous ownership of coins can perpetually rent-seek and censor the chain and there is no solution. In other words, a Proof of Stake 51% attack is game over - permanently. The controlling interest cannot be forked off the chain, and the community would need to essentially start a new chain (probably a Proof Of Work chain) to create a new, fair coin distribution.
- Clean energy development incentive: Contrary to common misconception, Proof of Work helps incentivise clean energy and is not the environmental disaster it is frequently villainised as.
The majority of "new" coins (say, 2016 launch or later) have chosen Proof Of Stake. This is because bootstrapping a large, secure mining industry in the way Bitcoin has is difficult and expensive. This doesn't prove Proof Of Stake's superiority so much as it indicts Proof Of Stake has a low barrier of entry and isn't that special.