You sure about that?
This takes out the USB Hub and likely anything on the same 5V supply line. Likely every controller. So while the data on the platters may be fine, any open files in cache is gone. Any encoded files via HDD bit locker are likely gone as you lost every controller in the box. The HDD controllers are all shot.
Getting the data off the HDD without any HDD controllers to reference means some major surgery. So it is now an issue of cost, so while the data is still there; is the cost to recover the data make it worthwhile? I am guessing recovery >$2,000
I've seen some motherboards that have been hit by surges with nothing left operational. RAM, Eproms, traces arced, nothing. But those were surges allowed through the power supply.
This USBKill attack, coming through the USB port, I will have to admit I am not sure how far the surge would get before enough damage would be done that components would be protected by destruction of other components acting as fuses or circuit breakers for other components further away from the USB port. I think it would be a crap shoot. Memory is volatile and would change with minor voltage/amperage variations before failure, so that would have to be considered as well.
I do know that the physical platters of a normal HD would likely be safe. I don't know about the memory on a solid state drive after such a surge and what condition it would be in.
I do agree, as I said, that economic decisions have to come into the equation when deciding about the value of the data recovery. I have actually told clients they would be better off junking a compromised but perfectly good OLD Windows PC computer and buying a new one, than to spend the money necessary to take the time and cost of wiping and restoring the OS, custom software, data, and configuring to the network of the old one, because they would then have a soon-to-be-obsolete model PC that would shortly need upgrading anyway and a new one would have the latest bells and whistles, and a faster processor with faster and more RAM, plus a new warranty, and the cost to install his custom software, data, and configuring on his network is the same. . . and he could usually take a Federal tax credit on all of it, that mere repair of the old one did not permit!
Of course all of this is predicated on there being an up-to-date backup. Too bad a lot of people got lazy about backups being made religiously.
Did you know that Apple removed the "Secure" erasure method of removing data on HDs from the menu? It's still available from the Terminal, but the reason it was removed is that it is totally unnecessary to be used on SSDs because no ghost data is left remaining when data is deleted from an SSD and because there is a finite number of times a memory location can cycle on an SSD, it is NOT a good idea to write random 0s and 1s to overwrite the original data on an SSD to obliterate the original data as that method did on magnetic media hard platters or floppy disks. So, to protect the longevity of SSDs, Apple removed the option. If you desire to secure erase a file from a physical HD, you'll have to use the Terminal command for that function.
I wish they had left the option, and merely used a routine to determine whether a user were trying to apply it to an SSD, and then just did the proper erasure technique as required, using a standard erase on an SSD, and the multiple random overwrite technique on a hard or floppy disk magnetic media storage. That would have preserved the secure erasure for everyone without having to jump through Terminal hoops of Unix commands.