Digital platforms offer substantial potential for sustainable consumption. Ridesharing platforms facilitate the sharing of rides, providing a convenient and cost-effective alternative to personal car usage. This reduction in personal car usage contributes to the mitigation of carbon dioxide emissions associated with mobility. Surplus food platforms facilitate the redistribution of surplus food, thereby addressing food waste. However, the utilization of these platforms in food and mobility provision does not necessarily guarantee these benefits. Furthermore, as they transform and disrupt existing consumption models, they may inadvertently lead to unintended consequences, such as increased consumption. Design fiction serves as an appropriate methodology to explore the potential benefits and drawbacks of Digital Provisioning Platforms (DPP) and their implications for sustainable consumption. In this paper, we present four food and mobility DPP fictions that address various aspects of sustainable consumption in food and mobility (i.e., Yesil Yarınlar, Mom-AI, Road Buddies, and Communa). These fictions were developed through two design fiction workshops conducted with 12 participants. Their reflections on these fictions revealed several tension points, which we categorized into three areas: Scalability and Impact, Cultural and Social Dimensions of Platforms, and Potential Rebound Effects on Sustainability. While presenting an alternative future for digital food and mobility DPP through design fictions, our work serves as a valuable resource for the design of new DPP in these domains.