It is when I delete it. I take the drives apart and crush the platters. Sure they could use electron microscopes or some other tech to read bits of data, if they could find the crushed platters.
1, it wasn’t my statement originally, and even at that I put some heavy caveats into it.
but mainly 2, yes, going well beyond electronic deletion to sanding the platens or burning/melting can certainly make them unrecoverable.
grinding the hard drives in a commercial shredder works well too.
That said, we are talking about simple electronic wipes, not destroying the actual media.