I don't know why it took me so long to figure it out, as I was ordering things from Amazon and Sainsbury, that I can, with some small limitations, not use the bank account at all, with the small caveat of needing to grease Amazon with some KYC before they let me use their gift cards.
For all the main budget, this literally means I can buy a little printer and print these codes out and never carry my phone or cards for these reasons.
Phenomenal.
Vouchers are a nice little sidestep from the banked vs unbanked question.
It made me think of an expression:
Living the prepaid life
<music notes> leaving less traces on the grid... <music notes>