Windows Defender isn't complete shit, but I have to wonder at the sudden push for Defender in so many articles recently.
Based on actual testing by AV-Comparatives
there are other, better options, some of which are even legally free.
I've been using Avira for years now, based on those results; Avira has one of the better if not best track records across all testing categories for years now. Downside, the freeware version does have a popup ad every so often. As far as spyware concerns, well, if you are concerned about your privacy on a Windows 10 PC, you've already lost. Format and install Linux.