Looking over what stripe is its actually a bit harder to answer that question. Thing thing about digital money is the ease of transactions without the need of a third party to do anything. In a game setting you can have full control over a wallet, track if transactions go through and have it be literally as seamless as buying or selling items on the auction house of an MMO.
When dealing with banks, fiat currency and such you have many more hurdles as well as the need for a third party to do anything.