There's no way that would be legal to sell. The whole point of the sugar in jam is preservation - you may get away with it for a while in a home canning scenario, but really a jam with 5% sugar is not shelf stable, and needs to be stored under refrigeration (commercial low sugar jams have to add an additional preservative like potassium sorbate instead).

In some jurisdiction, you cannot call that a jam, because you added foreign pectin. A jam must only use the fruit's natural pectin, plus sugar to activate the pectin.

It depends on the type of fruit though, since there are some fruits that won't set properly with the low-sugar pectin. (This only applies to home canning though, since the industrial manufacturers should have access to other thickeners.)

And I can make a bowl of cereal with a teaspoon of milk.