Everybody in these discussions always mention privacy, but there's an equally important consideration which seems to be often forgotten: reliability.

With electronic forms of money transfer, both the sender and the receiver need to have an account with some entity. There have been cases where pressure has been put on these entities to close someone's account, like for instance https://www.eff.org/deeplinks/2015/07/caving-government-pres... . With cash, there's no risk of someone closing your account, since it doesn't need one.

And, of course, there's the fact that all working electronic forms of money transfer I've seen are online; if the network is down, you can't do anything. Cash is offline.