I actually think we should just start an old-school crown corp that directly competes with the grocery stores. That's what crown corps used to do -push the private sector to do better through competition aimed at serving an important public need.

The crown corp could sell basic foods; produce, bread, simple meats and dairy products, and at a very low margin. The private grocers would have to compete either by tapping into that mysterious private-sector-efficiency to beat those prices, or via luxury grocery products that draw in customers. The crown corp could either build it's own supply chain, or rely on auctions, as needed.

It's a good idea. I see two problems with it out of the gate:

First, if it isn't accompanied by other changes, it will increase the equilibrium price of food until the poorest are just as squeezed as they are now, or maybe slightly less. "Other changes" could include price caps (perhaps voluntary -- grocery stores which agree to the program must also agree to a set of pricing regulations, and they would agree because it lowers their prices for the public without lowering their profit, meaning they have more customers who buy more), breaking up monopolies, or something drastic like a Crown grocery store chain. There could be other ideas too, but you'd have to do something to avoid it just being a subsidy to grocery giants.

Second, programs which are limited to specific foods often take weird stances about what is "acceptable" for poor people to buy. Not only does this rob them of dignity, it's often very poorly-managed, results in a lot of administrative overhead, and prevents people from buying things like fresh fruit, certain (even cheaper!) brands over others, or food compliant with their dietary restrictions. I'd instead advocate for either no restrictions on what food is purchased, or a blacklist where the card works in every participating grocery store for every product except explicitly excluded ones.

Okay but why on earth would we need to collect sensitive biometric data for that?

What's wrong with your name on the card and showing your ID? That's how worker discounts already work at Loblaws.

You're adding a massive security risk for no added benefit. This is the kind of thing I would expect Galen Weston himself to suggest, right after he purchases a controlling share in the fingerprint reader company.

Who pays for it? The issues come from the food supply chain charging more and more to increase profits, as well as other increased costs that get passed to the end customer.

I wouldn't support the cost coming out of the government as that just subsidizes corporations that are overcharging. Can they add competition in the food space to drive down costs? Can they mandate food pricing and profit limits instead?