I actually don't think it's that easy when playing a family with a few members in it. I spend a lot of time trying to make my sims happy while achieving the things they want in life and also improving their careers as well. I don't use any cheats other than the move objects cheat and I find that the game is in a good place difficulty wise.
I never really though of the sims as being a type of game that needed a difficulty setting. To me it's always been more about the experience of playing with artificial life and telling stories.