I was vegetarian for a while and then vegan for a whole year. I understand where you're coming from but it's simply not healthy for most people to go without any animal products in their diets, especially for growing children and those who cannot consume hight amounts of fiber (crohns disease). Perhaps the tax breaks enjoyed by the beef and dairy industries should be removed, but most sources of animal protein are remarkable environmentally friendly--farmed fishing is far less carbon intensive than almost all plant-based sources of protein[1]. Once you look at the facts of the matter, veganism has more to do with how someone feels about harming animals than actually helping the environment: most vegans still eat a lot of heavily processed foods, drive cars, fly on planes, have most of their food and consumer goods delivered to them via trucking. These are not issues that can be solved on an individual level but systemic and society wide problems that need to be addressed with public policy. No individual(s) are to be blamed. It is a collective, social responsibility.

[1]https://news.asu.edu/20190621-solutions-environmental-impact...