I am a bit late in this discussion.
But this is the second time I read this. Microsoft Defender is more safe then any of the Antivirus producers.
I think that those with a bad taste about MS Defender is from the XP period. Where it worked but was even below any of the free AV's.
Just been looking into some statistics, and I saw that indeed it was bad, back then. But every year they became a bit better.
Where I thnk that Defender in Win10 is better then the Win7 version.
The question now is, would I want to change from Windows 7 to Windows 10? Getting more security, but at the same time, handing over the content of all my mails and documents (Privacy issue).
This is a bit in contrast with Online Virtual Pilots Association - OVPA, where they demand a specific AV in case you would like to do Shared cockpit. They said it was because of several virtusses etc living in the wild, that would enter your pc via the connected port.