It's a reference to Chinese characters not having been further developed in the direction of sound-indicating writing (as was done later in Japan and Korea). Full historical details, based on quite recent archeology in China, can be found in the writings of William Boltz. I searched for some examples of his writings that are online and not behind a paywall, but didn't find any convenient examples. His observation is that Chinese almost went in the direction of explicit syllable-writing (as Japanese has had for several centuries in the katakana and hiragana writing systems) but development in that direction ceased during the Han dynasty.

P.S. I just found, by browsing, that the Wikipedia articles about Chinese writing still need a lot of clean-up. Too bad.

The Latin alphabet, or rather Phoenician, from which Hebrew, Arabic, Latin, Greek and Cyrillic scripts are descended, is more like 3500 years old.

But both the specific letter forms of the Roman alphabet and, more relevantly, the general spelling patterns of English are much more recent than that (as they would have to be). But, yes, writing is more ancient in the Near East than it is in China, for sure. It's just that it has gone through more language-specific adaptations, especially in the direction of exhaustively spelling all speech sounds with a minimal number of writing characters, than writing in China has.