And more food would get discarded and wasted. If one wanted to buy 1.5kg+ tomatoes, one would today. But people don’t.

Do you not think most people would just use paper bags and still buy smaller quantities?

No idea if most people but that’s what I do every time I visit an organic shop. I also bring my own bags.

It’s not like it isn’t possible today.

Possibly. Larger containers may need to use thicker plastic to be more sturdy, so there's likely to be some trade-offs.

Could be at the expense of more food wastage.

“food wastage” is not a real thing—non consumed food is perfect for composting and many other things. Organic materials literally cannot be wasted it gets 100% recycled.

Single use plastic on the other hand takes the scenic route straight into the ocean…