Let us review what your original claim was:
There is no proof that China has ever been more advanced than Japan
Chinese logograms predate Japanese kanas.
China was using a writing system before Japan was.
Modern Day Views
Nowadays there is more-or-less consensus on a few points concerning the origin of writing. First of all, writing was invented independently in at least three places, Mesopotamia, China, and Mesoamerica. Recent discoveries might also provide evidence that writing was invented in Egypt and Indus independently of Mesopotamia.
Ancient Scripts Origins of Writing Systems
Chinese writing, basically logographic
writing system, one of the world’s great
writing systems.
Like Semitic writing in the West, Chinese script was fundamental to the writing systems in the East. Until relatively recently, Chinese writing was more widely in use than alphabetic writing systems, and until the 18th century more than half of the world’s books were written in Chinese, including works of speculative thought, historical writings of a kind, and novels, along with writings on government and law.
It is not known when Chinese writing originated, but it apparently began to develop in the early 2nd millennium bc. The earliest known inscriptions, each of which contains between 10 and 60 characters incised on pieces of bone and tortoiseshell that were used for
oracular divination, date from the
Shang (or Yin) dynasty (18th–12th century bc), but, by then it was already a highly developed system, essentially similar to its present form. By 1400 bc the script included some 2,500 to 3,000 characters, most of which can be read to this day. Later stages in the development of Chinese writing include the
guwen (“ancient figures”) found in inscriptions from the late
Shang dynasty (
c. 1123 bc) and the early years of the
Zhou dynasty that followed. The major script of the
Zhou dynasty, which ruled from 1046 to 256 bc, was the
dazhuan (“great seal”), also called the
Zhou wen (“Zhou script”). By the end of the Zhou dynasty the
dazhuan had degenerated to some extent.
The script was fixed in its present form during the
Qin period (221–207 bc). The earliest graphs were schematic pictures of what they represented; the graph for
man resembled a standing figure, that for
woman depicted a kneeling figure.
Chinese writing -- Encyclopedia Britannica
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