A luxury some of us don’t have.
No, they typically aren’t, but it’s standard for vegans to avoid all animal products, whether the animal is slaughtered or not.
Like I said I have no problem with veganism, I’m not going to fault anyone for that choice, but not everyone can afford to make that choice, and it’s also not a magical cure-all for the problems of the world (and I know vegans who think it is.) If it were easy and cheap more people would do it. I personally would prefer to be a vegetarian for health reasons, but I’m not a good enough cook to keep my diet interesting and filling. I go through periods of vegetarianism, but end up falling back on meat, mostly chicken.