> In any case dealing with all this is too expensive and risky.

[Citation needed]

How much does it cost? How risky?

Let's say you are a bank and you make $10 on each $100K transfer. If customer disputes a transaction and you must return the money, you lose the whole amount and twice as much on lawyers, internal audit, compliance people working on the case. With this math you can't afford the risk if it is more than 1 in 30000.

For many European banks the math is even more brutal.