Glyph shapes are actually fairly arbitrary and probably aren't tied to innate readability. Most of the glyphs you and I know as Latin script came about from ancient Phoenician, which chose character shapes not for scanning, but for their similarity to a range of animals, plants and everyday objects.
The letter A, for example, comes from the Phoenician character aleph , which is modelled on an Ox's head (and as you'd expect, can be used to mean a cow, bull or calf).
Even individual fonts don't show as many innate readability features as we once suspected. Early studies in the 50s and 60s indicated that users could parse serif fonts far faster than sans-serif, but in the 80s and 90s that trend had reversed. The usual explanation is that familiarity, not glyph shape, is what principally determined readability.