Why can precambrian time not to be divided into periods by using fossils?

Precambrian time, which spans from the formation of the Earth about 4.6 billion years ago to roughly 541 million years ago, lacks distinct fossil records that characterize later geological periods. Most organisms during this time were simple and microscopic, primarily consisting of bacteria and single-celled organisms, making it difficult to establish clear stratigraphic boundaries. Additionally, the scarcity and preservation issues of Precambrian fossils hinder the ability to identify specific intervals or periods like those found in the Paleozoic, Mesozoic, and Cenozoic eras. As a result, the Precambrian is often divided into eons rather than periods.