The video addresses this. The biological term "fruit" is not accurate for culinary use. Lots of things we eat are biologically fruit, but you'd get weird looks for calling it a "fruit" while eating it. The video gives a lot of examples of botanical-fruit-but-not-culinary-fruit, including cucumbers, peppers, corn, eggplant, peas, pumpkins, and broccoli (specifically the buds).