Context: The global trend of landscape simplification for industrial agriculture is known to cause losses in biodiversity and ecosystem service diversity. Despite these problems being widely known, status quo trajectories driven by global economic growth and changing diets continue to lead to further landscape simplification. Objectives: In this perspective article, we argue that landscape simplification has negative consequences for a range of relational values, affecting the social-ecological relationships between people and nature, as well as the social relationships among people. A focus on relational values has been proposed to overcome the divide between intrinsic and instrumental values that people gain from nature. Results: We use a landscape sustainability science framing to examine the interconnections between ecological and social changes taking place in rural landscapes. We propose that increasingly rapid and extreme landscape simplification erodes human-nature connectedness, social relations, and the sense of agency of inhabitants—potentially to the point of severe erosion of relational values in extreme cases. We illustrate these hypothesized changes through four case studies from across the globe. Leaving the links between ecological, social-ecological and social dimensions of landscape change unattended could exacerbate disconnection from nature. Conclusion: A relational values perspective can shed new light on managing and restoring landscapes. Landscape sustainability science is ideally placed as an integrative space that can connect relevant insights from landscape ecology and work on relational values. We see local agency as a likely key ingredient to landscape sustainability that should be actively fostered in conservation and restoration projects.