How did writing systems, like chinese symbols that emerged during the bronze age, change over time?

Writing symbols in pictorial writing systems tend to simplify as time goes on because most symbols are drawing of the thing that simplify over time. So the answer would be they simplify over time and become linked with more basic words. Such as a scythe and a piece of hay meaning harvest. Harvest is linked to the symbols of hay and scythe, as time goes on the symbol for harvest will become more different from the original two symbols it was built on