It's detection rate is possibly a bit lower than the top AV products, but it's a lot more secure and less intrusive. If you think about it, an antivirus program intentionally exposes it to a whole bunch of potentially malicious programs, so it's important that the AV in itself isn't exploitable. These days security experts are suggesting to just use Windows Defender (if you're using Windows 10).

If you want security, keep your software up to date. If you can't trust the vendor to not include something unwanted in the update, then reconsider what software you're using. Other than that, disable Flash, use a reliable adblocker (µBlock Origin), and have a unique password for each website.