Gravel bikes need to employ a more modern cross country mtb geometry to be really capable offroad. Center of gravity is very important off-road so you don't go over your bars when hitting an unexpected rock or root or whatever on the trail. You want the bike to respond to a sudden change of direction quickly. Long stems with short reach do the opposite. At the end of the day I feel gravel should basically be cross country with a drop bar.
A good example of this is the evolution of cross country geometry as a whole. The norm used to be that cross country bikes were basically a road bike with flat bars. Because of this they handled like absolute crap on tech. Manufacturers started to employ a middle ground between your really slack enduro and steep road type geometry. Once that happened short travel bikes all of a sudden became incredibly capable and now you have 100-120mm travel mtbs that can pretty much handle anything you throw at them.