The current paper focuses on the Greek Social and Solidarity Economy (GSSE) and its undelivered promise for transformative local sustainable development. Our argument is that the GSSE is at an infant stage regarding the cultivation of its identity and its social impacts which deprives its potential to be a robust social economy paradigm able to address local development issues. Emphasis is placed on the role of Social Enterprises (SEs), and particularly on Social Cooperative Enterprises (SCEs/KOINSEPs in Greek) introduced by Law 4019/2011. Based on our analysis, factors traced in the macro, meso and micro environment could be considered responsible for KOINSEPs’ fragility and low contribution to the implementation of SDGs at local level. Firstly, an examination of KOINSEPs’ characteristics points to weaknesses that these entities exhibit in the Greek case. Secondly, an analysis is presented as to why these weaknesses are aggravated by the parameters at macro level such as the continuously altered legal/institutional environment and the unfulfilled “promises” regarding the creation of a favourable ecosystem. Thirdly, at meso level there is lack of local governance’s and other local actors’ support, low trust towards SSE organizations and poor local social capital. Fourthly, at micro (internal) level, the absence of strategic orientation and a clear vision, as well as the limited resources and the characteristics of the social entrepreneurs are underlined. Finally, directions for actions are discussed.