Source and examples? Note the focus on "independently" invented, and that I said "inspired or derived from nearby systems". There are many examples of writing

Source and examples? Note the focus on "independently" invented, and that I said "inspired or derived from nearby systems". There are many examples of writing systems that were made "from scratch" but only after contact with other civilizations that were already writing - e.g. the Korean Hangeul was designed from scratch, but only after millenia of Chinese literacy in Korea; and the Cherokee syllabary was designed from scratch, but only after centuries of contact with Western colonizers including access to their existing writing tools. If this is the kind of process you meant you meant with "multiple ancestral alphabets", I completely agree. But those were not "independent" inventions of "writing" as a concept. The idea of denoting ideas/sounds on paper is much harder to invent than the specific symbols mapped to each idea/sound. My understanding is that the consensus in the literature is that all writing systems in the Middle East were either derived from an existing writing system, or created from scratch after prolonged contact with neighboring civilizations that could already write, where these historical lines can be drawn all the way back to Hieroglyphs and Cuneiform. I believe there is little evidence to suggest multiple inventions of writing as a concept by isolated groups in the region. As for major writing systems that are still in use today across Europe, North Africa, the Middle East, and much of Asia, there's even less variety: I believe most of them are ultimately descended from Phoenician.