As I said similarly in a different thread:
Preservation would be increased if we take the principle used in many adventures: Split the game:
- A runner which can be ported and optimized, genre-specific
- the game core data (game logics and art)
- an editor
- a compiler (can be integrated inside of the editor or not)
- perhaps a graphics-optimized backend for the runner
You know, AGS does it this way and there's Scumm VM. Same with interactive fiction. And I think there are all-genre engines like Unity (and Godot?) who work this way.
Unfortunately this concept doesn't help rescuing old games. But it can make your game more long-lasting. You would only have to port the runner.
Edit: The idea to use emulators seems good to me for providing "usage" of old games.
Unfortunately there's another obstacle. Some games from the pre-internet era might be available only on floppy disks. And for example Amiga floppy disks are unreadable on a PC floppy drive.