There has been an increased interest in broader contexts from ecology and economics within the HCI community in recent years. These developments suggest that the HCI community should engage with and respond to concerns that are external to computing yet profoundly impact human society. In this paper we observe that taking these broader contexts into account yields a fundamentally different way to think about sustainable interaction design, one in which the designer's focus must be on a) ecological limits, b) creating designs and artifacts that do not further a cornucopian paradigm, and c) fundamental human needs. It can be hard to be responsive to these contexts in practical HCI work. To address this, we propose that the design rubric of disintermediation can serve as a unifying approach for work that aims to meet the ecological and economic challenges outlined in the literature. After discussing the potential use and impact of disintermedation, we perform an analysis using this design rubric to several key application areas.