Well, but the problem is: when is the money actually on your bank account? With BTC, as soon as the network mines a block with your transaction. With anything involving multiple banks or even cross-continent transfers, the delay will be >1 day minimum.

In my experience, debit/credit card refunds show up at my bank essentially instantly - my available balance reflects it within a minute the vast majority of the time.

Contrary to Bitcoins, your credit card does not scale.

Try to do a debit or refund of 150,000,000$ on your card. Cannot be done.

Bitcoin will happily do it's thing, either with 1$ or 150 M$ without discrimination, questions, etc... There lies the true power of Bitcoins.