Governance and Technological Challenge in Digital Solidarity Economies: A Case Study of a Collaborative Transportation Platform in South Korea

South Korea's City P illustrates how lofty goals of digital solidarity can falter when challenged by local governance realities. Drawing on Hansmann's ownership theory, collaborative governance concepts, and platform cooperativism, we conducted a qualitative case study involving policy documents, independent assessments, and 11 in-depth interviews with residents, officials, and technology developers. Findings reveal a marked disconnect between the initiative's stated emphasis on community co-ownership and the actual power dynamics that largely favored government agencies and external firms. Although blockchain and integrated digital tools were meant to enhance transparency and inclusivity, stakeholders--especially elderly residents--experienced confusion and mistrust. We argue that genuine collaboration in digital solidarity economies requires not only robust technical designs but also culturally resonant ownership structures, substantive inclusion of local voices, and transparent governance mechanisms. The City P case underscores the necessity of addressing heterogeneous digital capacities, aligning funding and incentives with grassroots empowerment, and mitigating performative participation to ensure meaningful and sustainable outcomes in community-based digital innovation.