piinyouri said:
Achievements/trophies.
Honestly, I'd like to have cheat codes make a comeback of sorts, but outright cheating devices were essentially mad serial killers let loose on a games internal code, slashing and rearranging as they saw fit, and it really wreaked havok with a lot of games, sometimes in the worst case scenario, rendering consoles unplayable over time.
I agree with piinyouri on this one, cheat devices, although fun when games weren't complicated, played around with internal code and although it's still possible, game developers are most likely wary that devices like this could mess with things they shouldn't mess with.
However I do wish the gta cheat system was brought back, where the developers made certain codes available just to make things more entertaining, I had countless experiences with these type things once I'd finished the games and in my opinion it was the biggest reason I played them for so long