I actually think if we added universal EBT/SNAP we could have the same effective pros of vouchers by having government-run supermarkets pop up. The “public option” would actually work for groceries, unlike healthcare (which should be universal).

EBT would save money building their own retailer and negotiating their own prices (or even enforced price regulation for them), which would force for-profit grocery stores to permanently compete against a non-profit-seeking competitor they would never be able to run out of business.