The fact is one has to understand the animal rights cause which I support away from diet. Which the vegans try and make into one. Animal testing, the circus, fur farms, leather industry, bull fighting and such all need to be banned. The Factory farms need to be banned as public health issue. However we are not vegan we still require not all plant food in our diet to be healthy the vegans can't argue this as they are the proof of such.
Vegetarianism I would state in my opinion with egg's seems to be more doable. You have the Adventist populations that show such it seems. But veganism has been around for 200 years and where is the vegan populations of intergeneration vegans..... They don't exist people had to fall back on animal products because all planet diets was not working. Even today many of the long term vegans who look decent are closet vegetarians.
The best that can be done is vegetarians create ethical farms. However the vegan ideology makes this impossible because they view this all somehow as slavery. In the end veganism leads to the animal holocaust because all these animals will be exterminated if everyone went vegan.