What do you use for freezing food if not plastic containers? Heating and microwaving, okay, I can work around the plastic containers/plates, but the freezer I have no idea how I'd do that. Especially that the freezer's casing is still plastic
They do have plastic lids most often, but the lid doesn't have to touch food.
The plastic issue is also why I think people doing sous-vide are insane. You’re vacuum sealing meat into plastic and then giving it a nice long leeching in hot water. Sometimes with acidic foodstuffs!