The four kinds of risk in payment

There are four risks in payment systems
• Credit risk (think over-indebtedness)
• Liquidity risk (think bank run)
• Operational risk (IT failure, strike, natural disaster...)
• Fraud

Decentralised systems like Monero remove the first two But the last two are another matter.

Failure on the whole network is less likely to happen than with a centralised system, but _more_ likely to happen localy: who never lost data on a hard drive and forgot to make backup? "In this sense, a digital wallet is more analogous to a physical wallet containing physical currency than a bank account accessed online."
Fraud is more probable at both the local and global level: 1) there is no cashback system for local protection and risks like 51% attack affect the whole economy, instantly.10
http://www.bankofengland.co.uk/publications/Documents/quarterlybulletin/2014/qb14q3digitalcurrenciesbitcoin1.pdf - page 10