BradFin

1. Do sensible units matter in a digital-payments-first world? There is no reason you couldn't divide up bitcoins into any number of arbitrary units with their own names. Similar to what we do with dollars. Your argument on this point is pretty flimsy.

2. Bitcoin itself is not well suited for small transactions. Unless something like the Lightning Network proves to work well at scale on bitcoin, enabling fast & small payments, this is not bitcoin's primary purpose. As it is today it's more a store of value than a means of of exchange. But bitcoin is far from the only cryptocurrency. Others do better here, and iteration is happening very quickly.

3. Most cryptocurrencies are very volatile currently, including bitcoin. Gold also has significant (though lower in recent history) volatility but that has not stopped it's use as a store of value. There is nothing inherent in a cryptocurrency that means it has to be volatile, nor that says a cryptocurrency/asset that is volatile today will stay similarly volatile.

Conclusion: You seem to be answering these questions as though bitcoin is the only cryptocurrency and as though the state of cryptocurrencies today is the state they will stay in for the foreseeable future. In my view each of these is a major error.