I think this is just semantics at this point, but to me there is a difference between “deleted” and “erased”. I see deleted as the typical “moved to trash” or rm action, with erased being overwritten bits, or like microwaving a drive.

Edit - If i remember correctly deleting something in most OS’s/File Systems just deletes the pointer to that file on disk. The data just hangs out until new data is written to that sector. The solution, other than the one you mentioned about encrypting stored data and destroying the key when you want the data “deleted”, would be to only ever store data in volatile memory. That would make for a horrendous user experience though.