Why does rice flour or cornstarch produce crispier crusts than wheat flour?

Question

If you add a percentage of rice flour or cornstarch to any sort of breading or pancake, you get a much crispier crust than one made with 100% wheat flour. The Vietnamese banh xeo, which is like a crepe made with just rice flour and coconut milk, no egg, comes out extremely crispy, for example. What is the physical reason that these pure starches cook up crispy?

Answer 1

My guess would be a lack of gluten in those flours. Gluten makes dough sticky and dense, so adding flours with little to no gluten might make it less sticky and thus crispier.