> The security model of Bitcoin comes from proof of work
This is not the security model, this is the consensus model. It's based on probabilistic finality, meaning that the probability that a transaction won't be reversed increases as more blocks are added on top. One major advantage of PoS is that it has "Absolute Finality" - after a certain amount of blocks, it's absolutely impossible to do a 51% attack. (See https://medium.com/mechanism-labs/finality-in-blockchain-con...)
Note that a higher hashrate does not mean more secure, it's a common falsehood. The security of bitcoin depends on the percentage of miners that are honest - this is mentioned the bitcoin whitepaper. Fortunately, the incentives align for the majority of miners to stay honest, and this is what the whitepaper predicted.
In addition, the Bitcoin proof of work is pretty much a proof of stake scheme in practice, where the stake are physical (specialized hardware and access to cheap electric power). So most of the GP's complaints about proof of stakes can be applied to bitcoin as well (“With proof of stake, the stakers only need to make an investment once in the beginning, so it results in rich get richer”).
And the biggest difference between BTC and ETH when it comes to “security” isn't “proof of work“ vs “proof of stake”, it's the fact that Vitali Buterin is alive and that there is an official centralized stewardship of ethereum, which in practice have led them to actually hard-fork the ethereum blockchain.
Proof of work is not a consensus model, it's a method to elect a block author, an incentive mechanism designed to keep miners honest.
Consensus is the process through which the network agrees on state. Examples are Nakamoto consensus (e.g. Bitcoin), BFT (e.g. Tendermind) or GRANDPA+BABE (Polkadot).
This is not the security model, this is the consensus model. It's based on probabilistic finality, meaning that the probability that a transaction won't be reversed increases as more blocks are added on top. One major advantage of PoS is that it has "Absolute Finality" - after a certain amount of blocks, it's absolutely impossible to do a 51% attack. (See https://medium.com/mechanism-labs/finality-in-blockchain-con...)
Note that a higher hashrate does not mean more secure, it's a common falsehood. The security of bitcoin depends on the percentage of miners that are honest - this is mentioned the bitcoin whitepaper. Fortunately, the incentives align for the majority of miners to stay honest, and this is what the whitepaper predicted.