Sculpting is a form of modelling. You can theoretically model (almost) anything without sculpting, but there are things that are just a lot easier to sculpt than to model otherwise….organic shapes are generally easier to sculpt, while hard surface (think for instance sci-fi spaceships) is much simpler with “classical” modelling (but they can be done with sculpting as well)…You can sculpt cloth, use a cloth simulation or use ‘edge by edge’ modelling and it’s partly a preference and partly depending on the situation which method is best…
I avoided sculpting for a long time, because I felt that I couldn’t do it. But then you come into a situation, where it is clear that even: first learning to sculpt this and then sculpting it will be faster and better than any other method…
What I am trying to say is: if you feel uncomfortable sculpting, don’t worry and start leaning other modelling methods…But, if you want to make dragons, learn sculpting 😉
It’s all a bit vague, but there are some ‘guidelines’, but no strict rules…you are free to do what you like and how you like it…