Define 'reliable long-term'. Roll-over to new tech is safe. The content of discussion is inherently reliable due to its digital nature. Keeping multiple copie

Define 'reliable long-term'. Roll-over to new tech is safe. The content of discussion is inherently reliable due to its digital nature. Keeping multiple copies is necessary practice and the long-time trend is that the next copy you produce has no greater cost than the previous copy (if you wait years, it will be significantly cheaper).