How to write in Cuneiform

> Like Japan’s kanji alphabet, the oldest writing system in the world is syllabic.

I think they have that mixed up with hiragana and katakana. Kanji are Chinese characters.

Well, if you call them kanji, they're Japanese characters. (Japanese characters with a name that literally means "Chinese characters", but still not Chinese characters.) Kanji are very much not syllabic.

But Chinese characters are.

Chinese characters are syllabic in the sense that most Chinese words are just one syllable. But still the characters have a meaning associated to them, that's why there can be dozens of characters that map to the same syllable.