Personally, I think Taoism is polytheism, because there are no missionaries influenced by Taoism. And there is no clear general doctrine for ordinary people.

Throughout the world-class religions:

Christianity, Islam, Buddhism, etc , have their own general principles, such as what goes around comes around, what God can do, to give the suffering people reasons to comfort themselves. Use some specific constraints to control the human heart in teaching, such as various commandments.

So they all have a large number of missionaries and fanatics.

The teachings of Taoism revolve around the theory of "nature and inaction". Those who truly understand and believe in Taoism do their best to understand the changes of heaven and earth and conform to nature, and naturally they are too lazy to win followers for their religion. It can even be said that pure Taoists have no divine belief, and even if they do, they are essentially humanistic beliefs, a kind of respect derived from life instinct.

Without advertising, there would be no market. Many ancient emperors used religion to consolidate their political power, used karma to reduce the crime rate, and used the belief of compassion to reassure the people. There are few things that Taoism can use. Song Huizong, who used Taoist teachings to consolidate his political power, came to a tragic end. Just because of blind pursuit of elixir and misinterpretation of doctrine. Ignorant people naturally can't understand things that the emperor himself is not sure about, so complaining has something to do with it.

To sum up, Taoism did not spread because its thought was close to metaphysics, which led to the disapproval of the mainstream society and the inability of the ruling class to use it, so it did not become a world religion.

PS: People who really guide themselves have their own independent thoughts; Just like the minds of a group of idealists will never form a ball.