What do you use to pay rent? That's the only use I still have for them, but landlords don't tend to take credit cards, and a check is easier than an envelope of cash.
I also miss things like BPay where I can pay all my bills via my Internet Banking portal. Moving to the US felt like a 10+ year regression in money related systems.
Cash is reserved for shady landlords and tax evasion.
Maybe GP can make them use Transferwise, Currencyfair or the like?