Most of it won't even exist. Around 100 years ago you would be talking about the silent film era, yes? Well what we have archived from then is just a tiny fraction of what was actually made. We can't begin to imagine what great works were lost for stupid reasons. And the archives we have a rarely delved into due to 'less than ideal' properties of nitrate film.
Even so, film is much more easily archived than digital media (you can just chuck it in a dark cave for 500 years and forget about it), what we may find is that some of the best bits of this era are lost to format obsolescence. You might not think it a problem with the formats you use, but those used in the media industry are very different and often change every 18 months. Maintaining a system of backups upon backups which have to be constantly updated and replaced is expensive.