Regarding packaging, growing up condiments were in glass. Good luck finding mayonnaise or ketchup in glass jars now. (I am able to find glass for my peanut butter and jelly fix — the peanut butter is some kind of natural stuff that you have to hand-mix though.)
While cereal is still in boxes, the lining/bag for the cereal was waxes paper (or waxed foil/paper if it was Super Sugar Crisp, emphasis mine).
I would love to see a branding campaign by some food conglomerate that introduced a line of glass (or wax paper) packaging for their products. I would absolutely pay a little more for that (although I wish it were the default again of course).
> Good luck finding mayonnaise or ketchup in glass jars now.
I've never seen ketchup in glass, but mayonnaise is sold in glass in all supermarkets in the Netherlands, as well as small aluminium tubes and plastic squeeze bottles.
Heinz ketchup is available in glass bottles and various other, smaller, companies offer it as well. Glass is pretty popular for "bio-ish products", at least in Germany (even though CO2eq-wise it'll usually be quite a lot worse than plastic packaging).