I'm all for having Physical copies of all media especially with how there are companies that will take out and alter content like the recent Skullgirls debacle, or how Netflix took out the Oh la la scene from Back to the Future 2 for a bit. Not to mention how so.e things have been taken off completely or possibly never available digitally like Tony Martin era Black Sabbath.
But I believe unless you have the Original Masters you're really not preserving anything.
From what I understand It's part of the reason why we don't tend to see Saturn era games re-released, and if we do they tend to be rebuilt. As back then after the game was finished and released it would then be deleted due to space so they could start work on the next game.
Unfortunately a lot of the original Master copies of Music have been lost due to a Universal Studios Fire in 2008. So if you ever wonder why a remastered album might not sound that good well now you know as it might be built up on a previous remaster/release.
https://en.m.wikipedia.org/wiki/2008_Universal_Studios_fireThis might be seen as a cynical take, but try to think of it this way... you have a copy of the Mona Lisa or any piece of art it would not be seen as preserving the art piece it would just be a copy and that's it.