I do not think anti-viruses are pure security theater. They will not protect against zero day attacks, however, once a specific virus hits enough people, anti-v

I do not think anti-viruses are pure security theater. They will not protect against zero day attacks, however, once a specific virus hits enough people, anti-viruses will be updated, preventing large scale infection. In order to avoid this, attackers need an attack vector that would allow them to change the virus binary at will. These definitely exist, but A/V does stop a non trivial amount of infections.