This was a huge advance, but it cannot be named as "inventing the alphabet".
It should be noted in this context, that Semitic languages can be written with comparatively less disambiguity with a consonant-only set of symbols, as the correct vowels can be inferred with relatively good accuracy from the consonants and the context. For Indo-European languages, such as Greek, this is not the case. However, even for Semitic languages a consonant-only writing-system was far from ideal. Thus, various strategies have been developed to reduce ambiguity, such as the use of plene scriptum[1] or punctation[2] in Hebrew.
https://one-from-nippon.ghost.io/story-of-the-emoji/
Doesn't talk about kaomoji though which I think are supercool. Like this table flip: ( ╯ ° □ ° ) ╯ ︵ ┻ ━ ┻