You misunderstand what "dispute resolution" means, at least in the context of someone proposing a blockchain as an alternative to PayPal.
Dispute resolution refers to a buyer and a seller who used the platform to transact a good having a dispute over the payment. PayPal can arbitrate such a dispute (in principle - your mileage will definitely vary) and either refund the payment to a defrauded buyer, or protect a seller from a buyer seeking to abuse the system.
Blockchains are entirely unable to help with this problem, as they are only a payment layer and have no information about things happening outside the blockchain itself, unlike PayPal.
Dispute resolution refers to a buyer and a seller who used the platform to transact a good having a dispute over the payment. PayPal can arbitrate such a dispute (in principle - your mileage will definitely vary) and either refund the payment to a defrauded buyer, or protect a seller from a buyer seeking to abuse the system.
Blockchains are entirely unable to help with this problem, as they are only a payment layer and have no information about things happening outside the blockchain itself, unlike PayPal.