What does it mean that Taoism has been closed for 500 years and closed for 300 years since the Ming Dynasty?

There were several disasters in the history of Taoism, and the Ming Dynasty was a disaster. After Zhu Yuanzhang ascended the throne, he knew that Taoism could come forth in large numbers, and he was not allowed to become an expert like Liu Bowen. So in order to keep the throne, he destroyed most Taoist books, and let Liu Bowen rewrite many Taoist classics, resulting in incomplete Taoist spells, and the spells handed down by Shi Tian were halved. I don't know that in the Ming Dynasty, they were more capable than Liu Bowen, but these people were not as secular as practicing in the mountains. Zhu Yuanzhang was simply carrying coals to Newcastle, which led to the loneliness of Taoism for many years.