We can’t eliminate all suffering and harm, so we shouldn’t even try reducing it? Perfect is the enemy of good. For many if not most vegans, it’s about minimizing harm. Many are motivated by ecological concern as well.

Some insects die on my car’s grill when I’m driving. I still go to work every day while calling myself vegan. Literally the only non-hypocritical action would be to kill myself. Forgive me if I don’t.