How did Laozi become the ancestor of Taoism?

Who said that Laozi was the ancestor of Taoism? Laozi has little to do with Taoism, which was founded by Zhang Daoling.

Before Zhang Daoling, there were Laozi and Zhuangzi, before Laozi and Zhuangzi, before Huangyan, and before Huangyan, there were Shennong and Fu, all of which were academic categories and collectively referred to as Taoism. Tao has existed for thousands of years since ancient times. The universe is the foundation, and heaven and earth are the laws.

Taoism, a sect that existed only after Zhang Daoling, has its own independent culture and system and has little to do with Taoism. If you have read Taoist books, you should know that Taoist books study fortune telling, ghost catching, exorcism and blessing.