GOG commits its own resources to maintain classic titles playable, now and in the future. We are launching the program with 100 games and will add more in the next few months.
At some point it just makes more sense to run emulators, like it is already done with the classic gaming consoles.
Ideally, we would get a push to release source after a given time, in order to have true conservation efforts.
7 Kingdoms had its source released and was almost instantly ported to run natively on Linux. And from someone who played that game as a teen and truly enjoyed it, I admit it's not that much of a game! There are thousands of titles that deserve this attention.
Off the top of my head I can think of:
Black&White
The Punisher (this title was even censored due to graphical content)