Earlier quoted context omitted.
The key distinction is that PoW is permissionless, whereas PoS is permissioned. Bitcoin is secured by hashpower, which is produced by physical capital outside the network. Nobody needs to ask for permission to start hashing and trade kilowatts for sats. PoS networks are secured by on-chain assets. This means you can't "mine" it without first buying tokens from someone who already owns them. You need permission from a…
>Another aspect of this is 51% attacks are recoverable for PoW, but are a permanent takeover condition for PoS networks. If a single entity ever accumulates more than half the tokens on a PoS network, they are unassailable. This is not true. PoS has many design flavours and the one Ethereum is planning on implementing includes random selection of validators and the amount staked has no influence on the inclusion or t…
If an actor pulled off a 51% attack on Ethereum I'd be surprised if there wasn't an effort to just hard fork them out of their resources.