The notion that Sequoyah was a monolingual Cherokee is dubious. He had a European father (though he was raised with his mother) and worked as a trader and served in the U.S. Army. His cousin, to whom he presented his syllabary, was also half European, “George Lowery.” He had extensive contact with Europeans. Moreover, his syllabary includes adaptations of Latin, Greek, and Cyrillic letters. He was obviously exposed to a variety of European writing. It seems highly unlikely that someone who was so linguistically gifted to be able to invent a syllabary would not have picked up some familiarity with spoken and written English through that exposure.

At least one counter-example: https://en.wikipedia.org/wiki/Hangul is technically an alphabet, and is non-Canaanite derived.

My understanding is it’s the earliest known alphabet but not the ancestor to all alphabetic languages as there are Asian and other alphabetic languages that are not derived from western or Arabic alphabets. Specifically Greek and Latin alphabets and their descendants are based on it. Specifically Japanese Hiragana and Katakana are syllabic alphabets derived from kanji (and Chinese pictograms) as a simplification of the pictographic language and not derived from proto sinaitic. Others are possibly linked, like Thai, Khmer, etc through an Aramaic -> Brami-> Pallava->Khmer linkage but the Brami link is not fully established to be true.

Very enjoyable documentary on this alphabetic development with relevant on-site visits.

https://www.amazon.com/A-to-Z-Season-1/dp/B0CWCHTM3B

Episode 2 then covers the printing press.

Technically, the proto-Sinaitic script is an abjad, with the Greek alphabet being the first true alphabet (symbols for both consonants and vowels).

Proto-Sinaitic/Phoenician can be described as the “first alphabetic system,” Greek the “first true alphabet.”

Fun fact: Greek is the world’s oldest recorded living language.

The Greek alphabet has been in use for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary.

Egyptian hieroglyphics already had alphabetic elements, and the canaanites borrowed those: https://en.wikipedia.org/wiki/Egyptian_hieroglyphs (“Egyptian hieroglyphs are the ultimate ancestor of the Phoenician alphabet, the first widely adopted phonetic writing system”).

Another counter-example is Phags Pa Script.

https://en.wikipedia.org/wiki/%CA%BCPhags-pa_script

The IPA still relies on convention to transcribe sounds. There's plenty of academic papers out there describing lesser studied languages and, if those conventions don't yet exist, the papers often contradict each other.

A writing system that used strict phonetic transcription for everything would be unusably bad. Everyone pronounces words differently than the writing system prescribes, in every language. Words are shortened and blended together constantly in connected speech.

Might be a mess linguistically, but it's sure nice to have only 26 letters with no accents on a keyboard.

Anyway I put in a request to get a copy at my local library so I will update here in a few months when I have a copy of the book.