How EFAIL broke end-to-end encrypted email

In my network security lecture, my group was tasked with creating a short video explaining the EFAIL vulnerability, which tricked email clients into sending decrypted S/MIME or OpenPGP message to an adversary. We shamelessly ripped off the format of the lovely YouTube channels Numberphile and Computerphile. I think the result turned out quite good, so I'm sharing it here for anyone interested.