I can't play without children.

I play a rotational style, and my play focuses mainly on young adults looking for love, getting married, and raising families. Once the children are grown and are establishing families of their own, yes, playing the parents can be a bit... well, boring. They are usually well-established in their careers and have no "storyline goals" of their own to pursue. Occasionally one family will be a little special, like my Edgar Evans family. He's a famous astronaut who is just about the reach the top of his career. His wife is a successful novelist, and they are still very much in love. I play them because I want to see them achieve the top positions in their fields, and also because Edgar is a fun goofball. He's constantly checking his social media to see how many followers he has. They've been a great couple, have raised two successful children, and I don't get bored with them.

Other "empty nest" parents may not be so much fun. Mostly they go to work, come home, eat, sit around and stare at each other, then go to bed. So, I sometimes mark them as "unplayed" and imagine that they've gone off to travel the world. I like having them around in the background, and I want to know when the grim reaper calls for them. (I age all my unplayed sims once each rotation.)

Sometimes it's fun to have elders who run businesses, but, sadly, as often as not, the older childless couples just aren't as interesting to play. :(