I talk about #lostmedia and media preservation sometimes (because I devote a somewhat significant amount of personal effort to the digitization, preservation, cataloging, and curation of various at risk or otherwise lost film and television programs. I talk about it because I'm working to overcome it!)
So I probably think about this more than most folks, I guess?
But do you ever consider how the magnitude of significance of the loss of any given piece of lost film is essentially unknowable?
We might have some contemporary press to depend on to tell us if a given film was good or not, but we might not! And even if we do, we have to trust them! The significance of a lot of films is only obvious in retrospect. Some of my favorite films were widely panned on initial release.
We'll never know what we lost.