Does that just slow down a sufficiently novated adversary?
Good enough to keep your data out of the hands of people who don't have access to a forensic lab and hundreds of hours to spend on it.
For HDDs, you need more accurate and sensitive heads to read magnetism with sufficient resolution and accuracy to correctly guess what the previous value may have been, sort sector bits from best to worst signal-to-noise ratio, then attempt every permutation stating with the worst bits until the sector error correction checks out. Rinse and repeat a billion times for a 4TB HDD. For an SSD, it is a similar process, except you need to strip the NAND layer by layer and record individual cell charges using an atomic force microscope or equivalent.
Your grumpy neighborhood long-bearded black-hat hacker is unlikely to have either of those in his basement.
BTW, if your data is top-secred SCI, hammer-erase is not be good enough since chip and HDD platter chunks large enough to be identifiable can still be read using an atomic force microscope. You still need to either secure-erase them first to make most individual chunks impossible to solve or grind them into a fine enough powder that there is very little chance any single piece carries intelligible data.
If you want to be absolutely certain nobody can recover data regardless of the amount of effort they are willing to put in it, you need molecular-scale destruction. For an HDD, you could fill it with salt + hydrogen peroxide to rust the platters off or bring the whole thing to the curie point at ~400C. NAND chips also self-erase in a similar way at ~600C.