While I’ll never (willingly) go Vegan I don’t think they’re completely wrong about everything. They do have some good points (they just try to build too much upon them).
I’d say they’re completely right that most modern people are alienated from and ignorant about the source of their food and would be repulsed if they knew more. Much of animal agriculture has been degraded by commerce and there are far too many inhumane practices allowed.
Factory farms are unhealthy and the animals have to be medicated too much and people end up eating that too. Too much meat of very poor quality (with too many chemicals and medicines) is produced and sold too cheaply and put in too many other foods.
The dairy industry is just as exploitative as the meat industry (with which it is intimately bound) and the egg industry is no better.
Fishing has its own problems with pollution and over fishing (and medicated treated water in many fish farms).
I completely agree with them about all this and with the idea that many or most people eat far too much meat and dairy and eggs of poor quality. They’re right about all of that.
What are they wrong about? …. Everything else.