[Hokusai]

People do what they see others doing, people buy what they see others buying, and what it is available in the supermarket.

If in 20 years it becomes difficult sand expensive to buy meat, would most people still center their diet around it?

Chicken and pork are way cheaper that plant-based alternatives. People cooking at home know many more receipts with meat that otherwise.

Societies have inertia. Good policies can move people, bad ones may delay change for decades.

In Sweden there are many vegetarians, most restaurants have vegetarian options as they do not want to miss a group of 5 because one person cannot find anything to eat. That makes it easier to go meat free, or at least reduce your meat consumption. Go to Japan, and even many vegetarians give up as restaurants make your life impossible if you want to avoid meat.