Ask a young adult today what a floppy disk is and you'll likely earn puzzled silence. To them, they are ancient artefacts. Demonstrate an "old" game (say, from around 2000) to a kid today, and they might look at it with disbelieving curiosity. Did games really look like that, once upon a time, in the unfathomable recesses of antiquity? Similarly, to me, 30 years old, games of the early 90s (and the machines that run them) already exude a certain alien primitivity. Revisiting them several decades after their prime with a historian's curiosity is as fascinating as it is frustrating: it's easy to bounce off old games and their archaic workings.
The advance and change of technology is rapid, and, as many have pointed out, presents daunting problems regarding the preservation of older games. But there are other issues that may be less urgent, issues that are just as real. Let's assume for the sake of speculation that game historians and preservationists manage to address the problem, and that, say, a thousand years from now (if we're still around by then), at least a fraction of today's games will still be playable in some form.
A thousand years may seem excessive. Given the breakneck cycles of hype and disinterest, of novelty and jadedness, surely no denizen of a future world a millennium from now will be interested in playing, say, Call of Duty: Infinite Warfare? But consider that when it comes to older media, literature first and foremost, some texts are still alive and well. You'll have no trouble finding a copy of Beowulf (ca. 1000 years old and surviving in a single manuscript which was almost destroyed in a fire in 1731), The Iliad (almost 3000 years old) or the Epic of Gilgamesh (a whopping 4000 years old). And it's not just historians who read them either.