The shape of Latin S arises from Greek Σ by dropping just one out of your 4 strokes of that letter. The (angular) S-condition made up of a few strokes existed to be a variant of the 4-stroke letter Σ already inside the epigraphy of Western Greek alphabets, and also https://bud-naked53086.ampblogs.com/the-bud-naked-pre-rolls-diaries-68117775