That's despite Europe having 2x the population of North America.
North America overall contains many more people than the EU. (340 + 129 + 40 for just USA, Mexico, Canada, plus another ~50MM in smaller countries. 560ish total)
These companies must be making bank.
It depends on how much cake you bake though. For many ingredients you'll need less than the smallest packaging size - and much less than packaging sizes that aren't way overpriced.