People who keep kosher or halal mostly avoid gelatin, so countries with notable kosher, halal, and vegetarian/vegan populations probably see less gelatin use.

Expert vegan here. No, gelatin is never in plain chocolates, but often added to diced coconut!

For chocolates it might be in things with foams or nougat. Definitely in marshmallows.

Ah. chocolates != chocolate

Usually nougat uses egg whites so it doesn't need gelatin as a protein. Marshmallows are arguably nougat, though, since they're also sugar bound with protein. Marshmallow cream usually uses egg.

All of the major nougat US candy bars I can find use egg and not gelatin.

I've seen chocolates with marshmallow in them.