'My antivirus is "not clicking on random things I don't understand". Served me perfectly well since the 80's,'
That approach has served me well, but it is not reliable. There are many ways to get malware even if you are careful. Many reputable sites have served up malware, as has *every* significant ad network. Even if you run an ad-blocker, a few still slip through.
My most dangerous compute exposure is when I need to run Windows for work, and must visit a range of work-required sites. For instance, when your job requires you to be part of a video conference / presentation that first requires downloading Java and Flash and running code from a slew of third and fourth party websites.