Reportedly US Banks are going the treat Bitcoin (BTC), Ethereum (ETH), and all crypto purchases same as Cash. In the crypto economy, this move is going to be a milestone. 
What difference does it make if they treat bitcoin and ethereum as cash. Are they doing it so that the government could identify these transaction so that you will be able to pay the taxes for every transactions you make with the bank to any exchanges ?. Apart from these i do not see any milestone as i am bound to pay my tax if i am converting the bitcoin to cash and i was doing that for the past few years. Maybe part of the growing bitcoin adoption. Let see, because there's tons of possibility that government want to somehow regulate cryptocurrency, but this doesn't directly mean bad for crypto, because in the first place, they cannot really interfere with blockchain and bitcoin in its technical aspects. What I find as a subject to government's regulation are the local exchanges because local exchanges should follow rules, laws, and regulations, thus people might pay taxes in the future through bitcoin conversion using these exchanges.
Going back, the statement of bitcoin and ethereum treated as cash is quite impossible, via definition
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money in coins or notes, as distinct from checks, money orders, or credit.
crypto has no physical tokens that has value.