Funnily enough, digital signals/data can actually be preserved perfectly and indefinitely because of its property perfect regeneration. Most efficient way to do it is to replicate it before it decays below regeneration. That one star review can outlast any stone tablet if it keeps on being copied.
Most things last very long if stored properly. People tend to not do that, though. Probably why low-maintenance, high-permanence formats tend to keep the best.