Let's forget about statistic. AV doesn't make your system immune from risks, but it's a good check. Perhaps going extreme, some vaccines are not 100% preventive (there are many that do). I download a file, run file check, and if I am still not convinced, I go to Virustotal to get more feedback. From experience there were a few malicious one passed by most of the AVs, because many AVs determine maliciousness based on same algorithms.

I get the idea that we should ditch an AV if vendor sucks at producing and maintaining the AV software, because that's literally inviting for a thief to stop by. You are better off reducing the risk exposure. But there is still a value to have one.

As with any software there are bugs. It just so happens Edge is shipped with Windows 10, and is also made by Microsoft. So should we give up on Chrome / FireFox / Opera because they also contain vulnerabilities but are made outside of Microsoft, which means we have another update schedule? No, because people value other browsers and most importantly Chrome and Firefox updates are so frequent we feel safe. If we assume AV vendors are as responsible as Chrome and Firefox developers, constantly pushing software updates so security bugs are fixed in no time, then why should we reject something that can be helpful?

How about Windows Defender? It's built-in, but doesn't have 100% successful rate in independent testing, and even so those are just samples that aren't like WannaCry, popping up out of nowhere.

So being able to defend the basic attacks is good enough. What really sucks is people are paying a lot of money for basic protection (and even more for the "Internet suite" and bundled with VPN etc). This is a true ripped off, but whether one is computer savvy or not, we can't take out a screw if all we have is bare hands and nothing else (nothing around you but on a lonely island without trees or plants or rocks but water and dirt). You can try by breaking the wall or the plank, but it would be a painful task. So take your risk. I won't stop you.