[abrookewood]

It's totally not required to wipe it/over write it more than once. I wish I could find the reference, but someone made a fairly comprehensive attempt to read data that had been over written once and they couldn't detect anything.

[crx087]

Not true, at least not under many conditions.

The required equipment makes magnetic data unlikely to be recoverable except in exclusive cases where certain government agencies with sophisticated labs get involved, but in short, storage leaves lasting (trace) physical changes behind.

SSDs and operating systems without proper Secure Erase support can very easily leave behind complete data.

[rasz]

SSDs are the least likely type of drive to leave anything behind due to Background Wear Leveling. https://articles.forensicfocus.com/2012/10/23/why-ssd-drives...