The links you posted say it was local files that had not been synced to Google Drive, so it's however long people were creating files that weren't synced to the cloud without the user noticing.

Some users are saying years but could it really be that long?

https://support.google.com/drive/answer/14286582?sjid=464734...

Great, then submit a link to the other reports, not a blog post that says 6 months and doesn't expand on that.