Each form of currency has its benefits and problems. For example gold: it is universally accepted as currency everywhere, it works without requiring computers, networks, electronics, or electricity. This makes it ideal for use where there is no electricity or networks. It is scarce and not easy to create. Gold is anonymous. However, gold is heavy, hard to store securely, difficult to divide into smaller pieces. Bitcoin is decentralized, easy to transfer to a third party, breaks into small pieces easily, has known quantity. However, Bitcoin can still be broken given quantum computing power. Bitcoin requires a sophisticated infrastructure of high speed networks and computer nodes making Bitcoin extremely brittle in the sense that a break in the chain can cause a failure. Having said that, the block chain is fine in terms of security. I am saying that when the infrastructure goes down, your bitcoins are stuck in the block chain until all the infrastructure comes back.