This is somewhat disingenuous. Transaction times can be as low as 10 minutes on Bitcoin, but this has high volatility. If I look in the past few months, average transaction times spike to a few hours quite frequently. Of course, if you look at the graph for January, the average transaction time jumped to days.

In standard interbank settling times, the transaction time takes days. But that's because transactions will automatically abort if they don't clear fast enough, and banks will take as much time as they can to actually close the transaction so as to avoid having to reverse it after the fact. In practice, many banks are happy to credit your balance with the deposit immediately (if the deposit is small enough, about $5k with my bank) without waiting for confirmation.

Of course, the time it takes to settle the transaction actually doesn't matter that much for the most part. In many cases, the transaction clearing time is going to be an insignificant portion of the time between invoicing the transaction and actually sending the goods.

And the reason for the spikes - blockchain technology struggles to handle large transaction volumes. The consensus mechanism monitors block creation time and tries to keep it at 10 minutes. Ideally, there are never more than a block's worth of transactions to be created at any given time. When that is not the case a backup occurs and yes, the settling takes far too long. This is the technical challenge that must be overcome before a PoW backed blockchain should be considered "viable" ready-for-prime-time. It is a significant engineering problem that I am excited to try to solve.

I transacted and settled with a physical fiat currency today in 10 seconds.

This is a perfectly cromulent response (see what I did there)?

I'd argue that you did not settle a transaction but more exchanged in a barter of one item for another. I am glad it worked out well for you and pray that you will experience continued expedient transactions in the future - blockchain-powered or not.

Nope, no barter - exchanged goods for currency, not for goods.

What would you mean by "settle" if you don't mean the point when the seller receives payment?

>Nope, no barter - exchanged goods for currency, not for goods Tomayto - tomahto amigo!

I mean when the seller receives payment. And I concede that there are banks that are releasing funds on a tighter timeline. But that decision is still backed by a credit requirement at some level and at the whim of a centralized bank. What they deign to grant to us they can also take away from us.

The current system is familiar and comforting but it is not the stable panacea we like to think it is in comparison to a scary blockchain. The stability is manufactured at the cost of the occasional blow-up - which we conveniently forget about as the market rebound to new and loftier heights.

Why does this matter? What can I do with ten minute settlements that I can't do with my debit card?

One of the ideas is that smaller payment amounts are viable on a blockchain - and there will be mining or transaction fees assessed but there will be fewer and smaller fees. Point-to-point transactability cuts out the ubiquitous payment middlemen and it gives the person making the transactions CONTROL of their transaction data. No longer will business pay credit companies to learn about you - they will have to pay YOU to learn about you.

Data is worth billions and trillions of dollars. And blockchain allows you to take control of it.