I always run an anti-malware security suite on my PC. Over the years I've made a point of running a variety of products.
At least for many years, perhaps more than ten, they've found no malware on my computers. None.
Perhaps I'm a more sophisticated user and I'm less likely to be taken off guard, but that can't be the whole answer. By the same token of expertise I take certain risks with dangerous files and sites that I would urge others to avoid like the plague.
But now comes news that could change the calculus: Independent test lab
AV-Test's December tests of Business security suites on Windows 10 showed marked improvement for Microsoft's anti-malware engine, the one that comes free for Windows 10 users as Windows Defender. This program used to be limited to "antispyware," a strange and purposeless distinction from malware generally.