it’s inefficient to really erase the data, so what happens usually is: it gets marked as deleted. the data only gets overwritten when another file is written in the same data area, which often doesn’t happen immediately. even if a drive gets formatted the empty metadata structures of the new partitions and file systems are just written on top. since they have no file entries yet, the previous data just sits there invisible and inaccessible until new files are created and maybe overwrite a bit of the old data.