In the past, video games often had cheat codes that a player could use of they found themselves in a difficult situation; I remember that the majority of side-scrolling DOS games that I played had such codes, and some games were simply too difficult to beat without them (a notable example being the third Commander Keen game). There were cheating devices for consoles, as well, the best known of these being the Game Genie and Game Shark.
However, in recent years, it seems that video games no longer have cheat codes, and consoles no longer have Game Genies or Game Sharks. Why is that? What has changed in the world of video games that caused programmers to decide to not include chest codes anymore? Are the games easier, and thus do not need the codes? Has the growth of online play and downloadable content rendered cheat codes unnecessary or unfair? What does everyone else say about this? Why do video games rarely have cheat codes anymore?