The more people on our side, the better? I mean surely you don't want to solely be beholden to a piece of plastic that can at any time be disabled, either intentionally, or because of an electrical or internet outage.
To answer your question though, I think cash still has a place. I value my privacy and wouldn't like cash to lose all utility. With that said, I do appreciate the convenience of being able to pay for more or less everything from my phone. It used to be frustrating when you'd run out of change to pay for parking, or had to stop at a cash machine to pay for a taxi. The only time I can think of over the past few months that I've actually used cash was for a particular takeaway that doesn't accept cards.