You are not wrong, I was talking about the "some long forgotten DVD on the attic" scenario when you suddenly find that you used some unusual image format to store your data for archival purpose because, e.g., you wanted to put more images on that DVD and now you don't know how to get it back because the only software that supports it is some Linux CLI tool that requires compilation with right flags to make it work. Or something even more arcane, who knows.

See digital dark age, though I am not talking about intergenerational problem - seeing how fast technology changes today and how more complex it becomes every day makes me think that such problems can happen even within our lifetime.