I was referring towhen I said that's not my experience.happening nearly every day, with restarts.
Additionally they often install an update that upsets what is already there...then you have to roll back.
I've no doubt that you can update Windows Defender without a Windows Update but you will be missing out on security updates to the operating system. Windows Defender and Malware Bytes alone may have done the job in the past, but that doesn't mean they will in the future.