They have done it in India. But to enforce such invasive law you would need powerful and organized ultra-nationalists and have to cause enough terrorism to scare everybody in the country and take control of the government.
You would need a very popular leader who can unite such fundamentalists, leaders like Adolf Hitler, Mussolini or current Modi, Putin or Khomeini. These types of Leaders have the capacity to ban meat consumption nationwide. Although India used to be a democratic country, but since the majority is Hindu, ultranationalists Hindu leader Modi was popular enough to enforce complete ban on Beef on most of the Indian states.
You can’t be just vegans, you have to have a extremist national leader with enough power to enforce any religiously invasive law. It’s already happened in Iran & India. And also in North Korea. In Iran they have Islamic invasive laws, in India there is hindu fundamentalism, in North Korea Kim Jong Un can do anything can enforce any law. Same thing in Saudi.