There are people who have genuine medical reasons to not take vaccines (e.g. an allergy to a common ingredient) or who are so immunocompromised that a vaccine won't keep them alive, and they rely on other people getting vaccinated to avoid dying. It's not just antivaxers who antivaxers kill.

Selection bias. All the survivors will say "See! We didn't need the Fauchi Ouchie!" while all the dead won't say anything.

I've straight up been at an event where a speaker asked "Raise your hand if you've died because you didn't get vaccinated! Nobody? That's what I thought."