Explain Why And Why Does Our Body Need Glucose-6-Phosphate

So in glycogenolysis, glycogen which is stored in the liver and muscles is converted to glucose-1-phosphate and then glucose-6-phosphate as a result to glucagon and epinephrine. The question is, why does our body need glucose-6-phosphate or glucose-1-phosphate? Glucose-1-phosphate is mostly useful as it can be converted to glucose-6-phosphate via an enzyme called phosphoglucomutase. However in glycogenesis, free glucose-1-phosphate can react with UTP in order to create UDP-glucose via the enzyme UDP-glucose pyrophosphorylase. From here it can return to the greater glycogen structure via glycogen