FWIW I have some old BBC B and ZX Spectrum cassettes from the early ‘80s that still work fine! I watch a lot of vintage computer restoration videos on YouTube etc and it is quite common for the HDD in old IBM XTs and early Macs to still be functional. By saying that I couldn’t get anything off a couple of my old PC hard drives when I tried recently, though they had been sitting down in a slightly damp cellar for a while (there was nothing important on them as I’d taken that before I scrapped them, I was just curious if there was anything else on there).
PS My first PC, a second hand IBM PS/2 Model 30 8086 DOS machine, had a 20MB HDD!