I’m not sure how practical/sustainable of a project this would be, but I feel that it could possibly be a useful project in the future if instances begin to purge old content due to storage constaints. The archiving service could store all the data using Object storage to archive it in read only. That way, at least people can still view old content in the possible scenario of rampant data loss across the Fediverse.
And Lemmy really isn’t either. Just like old reddit, it’s more forum than it is social media.
But on that note, forums are a form of social media.