Just like paper is not durable enough to be handled with bare hands, but the older tech of vellum is.

Github (a Micro$oft company!) has a shaft in a disused mine in cold, cold Svalbard storing Open Source software on film. None of yer wimpy NANDflash silicon, or ferrous oxide spinning disks. And they write using QR codes no less.

The takeaway is threefold. Github owned by Micro$oft, 1000 year film of some special formulation, and QR codes.

In 1000 years, digital archeologist will be able to see the development of software much like we hubristically opine on Roman culture from the residual scratches on wooden tablets.

AND

They are working on etching with lasers on quartz glass that will have a 10 millennia life span. Ready in a couple of years.

SO

Don't rely on those external HDD, SSD, or memory sticks for more than 5 years worst case.