Proof of Work vs Proof of Stake.
Money vs equity.

The core distinction

Proof of Work requires miners to expend real-world energy to propose a block. The block that gets added to the chain is the one backed by the most computational work. No amount of political influence, insider status, or accumulated wealth can substitute for the energy expenditure. The cost is physical and external to the system^[1].

Proof of Stake selects block proposers in proportion to the coins they hold and "stake" as collateral. Validators with more coins have more influence. Rewards compound: those with more coins earn more coins. There is no external cost and no external check. The system references only itself^[2].

As Lyn Alden framed it: PoW is money-like because it connects to real-world resources. PoS is equity-like because coinholders determine the ledger and the ledger determines the coinholders. "It would be like a political system where you get a vote for every hundred dollars you have, and also get paid a dollar by the government for casting each vote."^[2]

Ethereum's monetary policy: the hard numbers

Compare to Bitcoin: every satoshi that exists was earned through Proof of Work. The 21 million cap has never changed. The protocol has not hard-forked (all upgrades have been backward-compatible soft forks). Uptime: 100% since spring 2013^[2].

Ethereum's monetary policy has changed more times in 10 years than the US dollar's changed from 1900 to 1971. If you are evaluating a monetary asset, the stability of its issuance rules is load-bearing. A protocol whose community has demonstrated willingness to change the supply schedule, reverse transactions (the 2016 DAO fork), and replace the entire consensus mechanism is not operating under the same guarantees as one that has not.

The Blocksize War: decentralization under test

In 2017, the Bitcoin community faced the most significant governance crisis in its history. A coalition of major mining pools representing over 80% of hash power, the largest mining equipment manufacturer (Bitmain), major exchanges including Coinbase, and several prominent early developers attempted to push through SegWit2x, a hard fork that would double the block size.

They failed. Individual node operators, running nodes on home hardware with no economic leverage, rejected the fork. The upgrade could not activate because nodes refused to validate the new blocks. The corporate coalition capitulated^[2].

This was the empirical proof of Bitcoin's decentralization. Under Proof of Work, miners propose blocks but nodes validate them. A mining supermajority cannot force a rule change that full nodes reject. Under Proof of Stake, the validators ARE the economically powerful stakeholders. The 2017 equivalent on a PoS chain would likely have succeeded because the largest stakers were the ones pushing for the change.

The Blocksize War was not a bug. It was the security model working as designed. The fact that concentrated economic power could not override distributed consensus is what makes Bitcoin credible as sound money.

The stablecoin attack surface

On any PoS blockchain with significant DeFi activity, stablecoin custodians hold kingmaker power. Tether and USDC represent $115 billion+ in combined supply. In a contentious hard fork, whichever chain the stablecoin issuers recognize as "real" becomes the valuable chain, because the stablecoins on the other chain become worthless^[2].

This means the monetary policy of every PoS smart-contract chain is, in practice, subject to the decisions of two or three centralized companies incorporated under US law. Bitcoin has no equivalent attack surface. There are no stablecoins native to Bitcoin's base layer, no DeFi TVL to redirect, and no single entity whose decision determines which fork "wins."