That's largely solved by intermediaries, though. Much of our current economy can be re-created on top of Bitcoin. In this case, a credit card like intermediary would guarantee the transaction once they saw it, providing insurance against duplicate spending, so the recipient can get their money regardless.
Intermediaries kind of defeat part of the purpose of a decentralized system, but very very importantly, they're optional with such a system.
Intermediaries kind of defeat part of the purpose of a decentralized system, but very very importantly, they're optional with such a system.