That thought leads me to a paradox though, when we have robots taking over the one working sector that is left. So, in a future all-automated world the only work to do would be to design robots (if they don't just design themselves). So no people working = no salaries = no consumption. Am I missing something or from this perspective the paradigm is also doomed in the long run?
You're missing the fact that individuals can own and control capital such as robots. Of course their governments and vested interests will prevent them, so the paradigm is doomed in the long run.