I think the slow and expensive argument can be rebuted fairly easily. The traditional financial system is formed of many layers. At a high level, it is: centra

I think the slow and expensive argument can be rebuted fairly easily. The traditional financial system is formed of many layers. At a high level, it is: central banks, commercial banks, then card processors. You have to change your view to see Bitcoin as the settlement layer of this new anti-establishment currency, similar to how central banks settle today. That doesn't need to be fast, it needs to be secure. Bitcoin is pretty fast in settling relatively speaking, at least compared to other currencies.[1] It's important to look at the amount of value (electricity, power, money) that backs the block, instead of the raw block speed. People mistakenly compare block-time - look at Litecoin, it doesn’t matter if it has 4x faster blocks when 4 Litecoin blocks are worth many many times less than one Bitcoin block. The cost to reverse (51% attack) a transaction is much lower. If you agree with that view, then the Lightning Network[2] can be a promising solution to the slow and expensive argument. It isn't a 1:1 replacement to Bitcoin (someone else will likely need custody your coins if this scales to a global level), but it does solve the problem. As for the volatility, I think it's entirely expected to have extreme volatility as a currency is monetizing[3]. There's no real way for it to get from $0 to $2T of market cap in less than two decades (and perhaps go toward $20T) without large price appreciation and subsequent busts. Look at Apple stock as comparison. And it's not a fair comparison, because a stock has an underlying revenue stream that puts an implicit floor and ceiling to its price, whereas a monetary asset like Bitcoin doesn't. In essence, I believe it's premature to declare it "already failed" at being a currency. Although I agree that the signs of becoming a currency aren't strong. 1 - https://medium.com/@nic__carter/its-the-settlement-assurances-stupid-5dcd1c3f4e41 https://medium.com/@nic__carter/its-the-settlement-assurance... 2 - https://www.lynalden.com/lightning-network/ https://www.lynalden.com/lightning-network/ 3 - https://www.2minutebitcoin.org/blog/i-love-bitcoins-volatility https://www.2minutebitcoin.org/blog/i-love-bitcoins-volatili...