Just to add to this, fruit can be used to both cut out a lot of the sugar and to thicken sweet sauces as well.
Also, I just realized I could make date paste. (Something that never crossed my mind til reading your comment, 🙄. I’ve blended them fresh, but have never softened them).
As for caramel, I can find lots of things about sugar-free, but nothing on lowering the sugar content. “3 Ingredients Sugarfree Caramel Sauce” However, this video makes me think I could easily thicken and lower the sugar content of at least a buttery caramel. (Mental note to self; give that idea a try).