I'm pretty sure no AV would help against targeted attacks on high profile target. If you have multi-million business to secure, you play at totally different risk model.
On the other hand, AV usability is so bad you can't expect it to help "normal" people. All those popups do more harm than good when people start ignoring them.
In this case, there are much bigger problems than the lack of AV.
Maybe the perception that you can achieve some kind of security through band-aid solutions is exactly the cause for the lacking security of many organizations?
Isn't that a case of the survivorship bias? Or at least the broader case of selection bias?