He picked a bad example; a better one would be ice cream.
Formerly sold (most commonly) in half-gallon containers, now it’s a quart-and-a-half.
Or toilet paper. There was a time the standard sheet was 4.5” x 4.5”. I’ve seen it as small as 3.7 x 3.9 in the modern era.
Or a pound of coffee - now 11 or 13 ounces.
Or what used to be a pound of bacon coming in at 12 ounces to a package.