[spookthesunset]

> but perhaps it could be cheaper than the cost to build and maintain Guarda/Loomis trucks that carry physical currency, energy to melt metal to mint coins, and all the costs of building brick&mortar banks

On a per-transaction basis? I don't even need to work out the math to tell me it isn't even close. Bitcoin can at most handle 4 transactions per second. By virtue of its very design it will never get much more than that. Our existing financial institutions process tens or even hundreds of thousands of transactions every second. Even if the entire worldwide financial industry consumed as much power as bitcoin, on a per-transaction basis (or even a per-dollar/euro/yen basis) our existing system is much, much, much, much, much more efficient.

Just to again emphasise, Bitcoin (and hence the blockchain) by design cannot scale much more than it already has. It is simply impossible without giving up all of Bitcoin's attributes that people consider important (decentralization, trustless trust, etc...)

[em3rgent0rdr]

The Lightning Network (which has just reached version 1.0 and demonstrated successful transaction) doesn't have such transaction limits.