Earlier quoted context omitted.
> You cannot have a trustless consensus without a mining incentive This is not true, Proof-of-stake creates a suitable incentive to verify transactions and maintain the network. It's a legitimate alternative to proof-of-work.
You understood OP wrong. He is not saying that PoW is the only viable method of securing the chain, but rather, that you need a mining incentive . There is such a mining incentive in proof-of-stake, block signers get rewarded.
> There is such a mining incentive in proof-of-stake, block signers get rewarded.
Not in all PoS coins, actually. And arguably you don't need it. Your stake's value is contingent on fulfilling the implicit promise of the network: honest, accurate, fast transactions.