Why is the patent application so slow?

You mean that an invention is really slow to get a certificate because it needs substantive examination. The so-called substantive examination means that you need to consult all the relevant patent documents in the world to see if your patent is similar to others' patents. This is a relatively large project, and there are so many patent documents every year that people from the State Information Bureau can't review them, so it's very slow. As for what you said, "because if you wait for a patent to apply for reproduction, then the technology may fall behind the times and not become the value of the product." As long as your application documents are made public, this product should be ready for production. Generally speaking, it only takes a few months to submit the application documents!