Why is non-patented technology as wrong as patented technology with a time limit?

There is confidential technology in non-patented technology, and there is no time limit for confidential technology unless it is stolen.

For example, the formula of Coca-Cola is confidential technology and belongs to non-patented technology.

Non-patented technology does not need to disclose the details of patents, so others have no way of knowing what non-patented technology is like.