I got anxious, too.
Then I decided to take things under my control and start using this cheat:
sims.age_up
After many cheat codes were disabled with a patch, I had to download a mod so I can use that cheat.
One of the reasons is that I want them to show in the family tree in everyday clothing.
Another is that a sim who I helped to develop their skills is going to die. They should leave something behind as a painting or a photo.
Third reason is the culling. Yes, with cheats ghosts can be added to the household, but the ghost will then count towards the household limit. Yes, the culled ghosts will stay in the family tree, but after one patch, some of the ghosts disappeared from the family tree. It still makes me anxious. I even built a building full of pictures of sims who are and were in my game in played household. Each time someone dies, I'll make their picture black and white. It's great to remember, who were in the game, but it's annoying to do it for every played sim (I'm a rotational player).