I mean it deserves to be lost forever in that it has no artistic or ideological merit. Mein Kampf deserves to be lost. But we deserve to keep it as a warning so that we do not repeat history. But if humanity could grow to the point that such warnings are never needed again, and if the book could be forgotten due to losing all present and future relevance, that would be a good thing. What a thing deserves is sometimes different to what is necessary or good.