Education is how we win, and it is slow because it has to undo the cultural normalization of meat as an identity. The meat industry has spent decades lobbying for subsidies and advertising meat as part of the American way of life.
It is really hard to fight that because once something becomes part of a person's sense of self, attacking it engages the ego. It is the same issue with car dominance.
I think it is important to keep in mind that victory is not an all or nothing game. A lot of leftist ideals interlock with a thought structure that makes people more open to persuasion through reason.
That change comes a little bit at a time, not by one well reasoned argument, but by seeing happy, thriving communities as living proof.