Jam is a pretty sweet product, but that doesn't mean I'd expect I'd expect more sweeteners than fruit. A basic recipe for strawberry jam might require a couple pounds of strawberries and a couple cups of sugar. That'd still have a shelf life of a year or more (unopened).

But sugar is literally added to jelly as the preservative, that's why jelly exists to begin with.

For example, the very first recipe for strawberry jelly from some horrible spam recipe site:

2 cups (16 ounces) pure strawberry juice (I used 3 1/2 pounds ripe, fresh strawberries to get this amount of juice) 3 1/3 cups (666 grams) granulated sugar

It's literally more sugar than strawberry juice.

Or maybe you would expect more sweetener. What's wrong with honesty in labeling?