To summarize, designing a centralized payment architecture is much easier than designing a decentralized one. However, the centralized model presents security threats from hacks, because there is a clear and attractive target for such attacks. A centralized system also presents a more expensive and inefficient solution for customers, because it tends to create monopolies, or cartels. This concentrates market power in the hands of a small group of intermediaries, which can extract disproportionately large values, in the form of transaction fees. The customer outcomes resulting from the legacy financial infrastructure are expensive, slow transactions. This sector has not seen any major innovations in a very long time, and it is ripe for disruption.
In contrast, a decentralized payment network, such as Bitcoin, implements the more difficult solution of decentralized consensus in transaction processing. This design enables it to deliver a much more efficient solution for all parties involved. Payments go directly from peer to peer, and security and processing are guaranteed by the entire network. Funds are sent and received in a matter of minutes. All of the network participants maintain a consensus of the current state of the transaction ledger, at all times.