Earlier quoted context omitted.
I think we (or our descendants) will be surprised by the longevity of some of the file formats in use today. I would wager that it will be possible and not too unusual for regular users to open files in formats like PDF, zip or jpeg 100 years after their inception.
You think we will still have files? I wager in the long term we're going more towards a people focused than paper focused system.
I.e, we will still be able to store and transfer sequences of bytes conforming to some specification (file format), and we will be able to attach names to those blobs in some namespace. The concept is too general to ever lose its usefulness.
There are a few key things I have learned in the third of a century that I've been working with data: Data lives longer than apps and longer than people. We will always need units of data that have their own life cycle and are reasonably self describing and self contained (i.e meaningful without resolving external references).