Both plants store carbohydrate as inulin-type fructans rather than starch.
Not because chicory is inferior. It isn't. Because source, grade and supply should fit the formulation and the sourcing strategy.
Inulin does not win every column. It is useful because it combines prebiotic function with food-formulation functionality: fiber, body and bulk in one ingredient.
Qualitative, general characteristics of ingredient classes. Individual commercial grades vary. Inulin row highlighted.