It is nearly impossible to overstate the influence behavioral economics now has in academic science and applications to policy. Essentially all domains covered in public and political debates – from social services to social media – are now fair game for interventions derived from psychological science and their subsequent evaluations. While this trend may have started over a decade ago and certainly existed long before that, a number of prevailing concerns have overshadowed behavioral economics as a field of scientific study, which could be summarized simply as “But why?” In this concluding chapter, we critically review the concepts and cases discussed in the preceding chapters, highlighting strengths and general insights, as well as pointing out concerns regarding ethics, failures of behavioral policy, and the lack of a cohesive theoretical framework. This chapter seeks to explain why combining psychology and behavioral economics seems to be such an effective tool as opposed to merely being an interesting experimental technique. We use all of these topics to highlight the most critical insights across the field, as well as what it could mean for the future of policymaking, its impact on economic stability, and most importantly, its impact on improving the well-being of entire populations.