We have to do it. Some of us have to do it in different ways. Doing small things where you can is all well and good but literally none of us are making a single impact in capitalism by making different choices about how we're forced to participate in it. Focus on tearing it down together rather than picking apart individual choices because those individual choices still result in participating in capitalism.
Actually, it doesn't change anything because the markets aren't responsive enough to adjust how many animals are slaughtered based on a single person's day-to-day consumption habits.
The comparison to child labor is apt.
Sorry if that makes you feel less morally superior.