I've posted it before, but when I saw that Microsoft Defender sends your files to be inspected, and has no audit history of what goes from your computer to their servers, I installed Linux.
Automatic sample submission
Send sample files to Microsoft to help protect you and others from potential threats.
We'll prompt you if the file we need is likely to contain personal information.
Regarding that last sentence, it is not documented what they consider "likely to contain personal information".