The OP does have some truth to it. All the ancient alphabets I know of (with two or three exceptions) have some connection to ancient Semitic script, which was developed by adapting some Egyptian hieroglyphs to make the Sinaitic script which was the precursor of Phoenician.
One exception is the Ancient Persian alphabet used in the Behistun inscriptions, which borrowed cuneiform characters from Mesopotamia and used them phonetically.
Another is the Tifinagh script used by ancient Lybico-Berber peoples, which has survived in use until today by the Tuareg of the Sahara. I don’t know how it started, but it does not seem to have any connection to Phoenician.
Epigraphic South Arabian (ESA) used in Himyaritic inscriptions in ancient Yemen does not have much resemblance to Phoenician letters that I can tell. Perhaps some ESA letters were borrowed from the same North Semitic source as Phoenician, while others were invented in Yemen. ESA is the direct ancestor of Ethiopic syllabic script still used in Ethiopia and Eritrea today.
Middle Persian was written with an Aramaic alphabet descended from the same source as the Phoenician. Alphabet borrowing across Asia went like this:
Aramaic > Pahlavi > Sogdian > Uyghur > Mongolian > Manchu
So the Aramaic alphabet traveled clear across the continent of Asia, from the Mediterranean to the Yellow Sea, in premodern times. Must have had something going for it.
I would not say that the Arabic alphabet was “derived from Hebrew.” Rather, both alphabets came from a common ancient Semitic source. The immediate ancestor of the Arabic alphabet was the Nabatean script. You can find resemblance between Arabic and Hebrew letter shapes, especially if you go back to the earliest forms of Kufic Arabic writing, and especially if you squint hard and look sideways.
Little-known fact: What we nowadays call the “Hebrew alphabet,” the square-letter thing, is in reality the ancient Aramaic alphabet that was borrowed for use with Hebrew. The real ancient Hebrew alphabet was the same as Phoenician.
The Devanagari alphabet used for writing Sanskrit is a relatively recent development. It is descended from an ancient alphabet called Brahmi, which in turn seems to have been based upon Aramaic. Brahmi is the ancestor of all the Indian alphabets, in addition to Tibetan and the alphabets of Southeast Asia.
Prior to the adoption of Brahmi script in India, the Vedas were oral literature going back to immeasurably ancient prehistoric origins. Yes, they were all memorized and recited aloud. An enormous amount of memorization, but without the crutch of writing, ancient peoples managed to memorize gigantic oral epics.
The Orkhon Turkic runes used in 6th-7th century inscriptions probably had an Aramaic basis too. These runes, unconnected to Germanic runes, survived in use by the Székely people of Hungary until the 19th century.
The Korean alphabet introduced by King Sejong was invented independently of all these alphabets derived from ancient Semitic writing. It is truly original.
In modern times, several alphabets have been invented that have no connection to ancient Semitic. Joseph Smith invented a weird Mormon alphabet.
A gentleman in 20th-century Somalia named Osman invented the Osmani alphabet, which he proposed for writing the Somali language. It was not adopted and is now forgotten.
Someone in Africa invented an alphabet for writing Bantu languages, inspired by modern phonetic science, in which the letters are diagrams showing the mouth positions used to articulate the sounds. However, the overall framework of the speech organs remains pretty much the same and the differences are small in relation to the whole picture. This makes it hard to tell the letters apart; they mostly look the same.
The b and p in Devanagari have two completely different forms. You’re thinking of the unaspirated p and the aspirated ph; the latter is differentiated by the extra curly stroke you mentioned.
Great name! Best books ever!