Some cuttings that are rooted in water will form roots, but the roots may be too weak to make the transition to being planted in soil.
I usually root my cuttings in damp vermiculite. When I lift the cuttings they have a strong root system, some vermiculite adheres to the roots and the plants easily make the change to being planted in soil. For me it is 'trail and error' to know which plants like to root in water and which prefer to root in other medium. I am sure someone with more experience will come along with a better answer.