Unlike other art forms, video game preservation has never really been up to snuff. While structures are in place to make sure old TV shows, books and films are constantly in print, preserved to the best of their owner's ability in order to maintain their original quality, gaming releases don't enjoy the same care and attention.
Disregarding emulation, trying to return to an old game from a previous generation often means you need to be lucky enough to stumble across a second-hand copy of the title itself, own the right console to play it on, and have the correct input and output cables to actually make it work. Even doing all this won't guarantee that the game will play as it did when it was first released, as its servers may have been turned off, leaving a huge part of its functionality inaccessible.
Worse still, licensing issues might make it virtually impossible to buy the game in the first place, seeing it removed from digital storefronts and recalled from stores, only able to be bought for inflated prices in second-hand shops or online. As a result, there's a plethora of excellent video games - both recent and old - that are a shell of their former selves or, even worse, unable to be played at all.