Software debloating seeks to mitigate security risks and improve performance by eliminating unnecessary code. In recent years, a plethora of debloating tools have been developed, creating a dense and varied landscape. Several studies have delved into the literature, focusing on comparative analysis of these tools. To build upon these efforts, this paper presents a comprehensive systematization of knowledge (SoK) of the software debloating landscape. We conceptualize the software debloating workflow, which serves as the basis for developing a multilevel taxonomy. This framework classifies debloating tools according to their input/output artifacts, debloating strategies, and evaluation criteria. Lastly, we apply the taxonomy to pinpoint open problems in the field, which, together with the SoK, provide a foundational reference for researchers aiming to improve software security and efficiency through debloating.