As a computer nerd who is confident about identifying shady websites or email attachments, I do not use any anti-virus software. All of my important files are backed up, and I know how to reinstall an OS. I'm sure I can probably be tricked eventually, but if I am, my over-confidence will result in me ignoring any security warnings from anti-virus software, so it won't help.

Don't use it in 2019, just as I didn't in 2009, or in 1999.

Furthermore, have had to remove it from plenty of machines of non-techie people asking for support, where it was not only doing NOTHING to protect them, but also preventing their systems from working as intended.

Now, if you want to talk about uBlock Origin and the likes though, that's a good conversation to have these days about actually essential protection.

Times have changed. The biggest virus today is convenience.

I do not. Window’s built-in stuff and plain macOS are very good these days. I’m not very convinced that third party anti-virus software provides much additional value. Would love to hear an expert’s thoughts on this subject!

Windows 10 of 2019 is much much more safer than windows 7 or xp as example. Much safer security defaults and dozen more security features. So firewall, hosts and unlock origin is what I use. Backups also. Sometimes I do test on VM or via clamav. Defender is off. I did setup 'run only from predefined folders policy' and non admin users for my relatives.

I still install antivirus software, but given the feedback from you guys - I'm not sure it's still worth it.

What can I say, I moonlighted as a computer technician during W95-Win7 years and old habits die hard.

I don't. I found anti-virus software slows machines down (especially live scanning) and causes some of the very same problems as malware.

Antivirus is like taking penacillin because you eat food from a dodgy takeaway. Instead just eat at trustworthy places.

Linux.

Using Linux will not save you.

Have you ever used Qubes?