Here’s my latest comic: https://inhumaneresourcescomic.com/#/panel/684.
I researched this point a while ago. It occurred to me that the cape was the weirdest part of a superhero’s outfit, and I wanted to know why superheros had them. A bit of Googling brought me to Charlotte’s answer that they all come from Zorro.
The social commentary in the last panel is more blunt than I usually get.