I think the problem has and always will be automation. The smarter that we become as a species, the more advanced and sophisticated our tools start to become. This trust-less Eco system is handled partly by automated processes. We've come to rely on computers and internet connectivity in order to pull it off. I don't think Bitcoin was really possible before their were computers. It was only a matter of time before some kind of automated platform and system emerged that would make transactions faster and digital.