Excluding existing archiving sites, do you have an expectation or think that data stored on lemmy should be permanent? E.g last 20+ years. Would it matter if old inactive content was culled? If you had the ability to export data if a sever was due to go down, what would you actually do with it.
But is it? History is written from the scraps that historians have dug up. Often we mostly get the experience of the ruling or intellectual class of the day. Other times we only have artifacts to go on. The greater persistence that data has today will let historians looking back reconstruct history more accurately, especially for capturing the views of the average citizen given that literacy is near universal.