It's irresponsible to make such a broad claim and back it up with really vague anecdotal evidence. Yes, there are a lot of lousy AV products that are at best a break-even for security, but there are some that don't suck and generally you have to pay for them - what a strange concept.

I'm not going to advocate for any particular vendor as I used to work for an AV company (and currently use a product from a competitor). But I can attest that I've used products that have caught threats that Windows Defender didn't, and many products also include a much more robust and configurable firewall.

It's annoying when someone else's lousy code breaks your own code. This happens to the sites I administer frequently, where we will randomly get blacklisted by some no-name AV product's web security feature. I understand the frustration when you have no control over this. But to conclude that all AV software is bad does not follow from the evidence given.