Wouldn't it be centralised if protocol checks the transactions? It is just like a bank, they only checks your balance and deduct amount when you transfer money. It wouldn't be decentralized and considered as p2p as a centralised program checks the transactions. It would function like a bank if only the protocol verifies transactions which isn't what people want.
I think it's different from a bank. There's just the protocol running, not controlled by anyone, no one who can decide whether to allow a transaction or not.
Thanks for the link. Is it really centralized if everyone uses the same protocol which isn't controlled by an institution? It could be completely transparent.
Bank function the same way, deduct money once you make a transaction without verifying the legitimacy of your transaction cryptographically. If the protocol is verifying the transaction without the community verify it themselves, it is almost equal to it being centralised as only it can verify the transaction and approve them.
If a hacker manage to hack and change the protocol, it can block everyone else transaction from being verified and deduct money from everyone else account. If mining pool is used, no one can block transaction from being verified unless they have 51% of mining power which is expensive and it cannot control anyone else's account. That is the point of bitcoin isn't it? Being able to have full control of your coins without someone actually respond to your request and transfer the amount.