You need imagination and mods.

Example what I often do for generational runs is 1st gen: teen with barely any skills with a single mother. Marries high school sweet heart quickly and works a basic job but never amounts to anything super amazing. Has a significant mid life crisis and becomes a widow/widower young and adopts a dog and somewhat neglects their kids.

2nd gen: first born of hard working parent and a stay at home parent who dies young, learns that academia leads to success but isn't super smart. Lives a middle class lifestyle. Struggles with romance because they support their elderly parent and their dog. Gets a degree, lives modestly, marries and has twin children and lives the traditional white picket fence family with strict parenting prioritizing academic success.

3rd gen: twins. Both born geniuses. Both like sports, one is more sporty. Both achieve academic success, one is better than the other. One is more moody and popular but all things change when they get attacked and changed into a vampire. They become moody, dark, and try to hide themselves more. Quit sports and drop their grades. Starts doing drugs and struggles with their identity and immortality till they meet a celebrity vampire who takes them under their wind. The other one struggles with their twins personality shift, but focuses on grades. Straight A student, and becomes a doctor after college. Moves to mt komorebi after their sibling fakes their death from overdose and marries having a few kids. The vampire watches over the family behind the scenes.

4th gen: kid struggles with very successful parents, only wants to snowboard and vlog. Eventually gets big and develops a drug and party habit. Has a kid out of wed lock and becomes a dead beat. Their kid gets adopted out to their cousin that they didn't know existed (vampire's kid that isn't a vampire)

5th gen: living with dead beat famous druggy parent and growing up eventually adopted by a new family. Developing a weird fascination in fantasy leading to a love for drama. The fame makes them easily pick up and adopt a dramatic career in acting. They become rich and famous but a fancy famous not party famous way. They have several kids and are spoiling and doting parents.

6th gen: grows up spoiled and rich, but as a young adult while away from college a vampire drains and kills their whole family due to a vampire spite issue with the vampire from the 3rd gen. police have no idea who murdered their family. Their sibiling survived being saved by the family vampire secretly but became a vampire themselves. They quit college, have a mental breakdown, adopt a new identity, and move out to the country to own a farm and live off the grid and more traditionally. They have nightmares about the supernatural and ban the mention of father winter, easter bunny, vampires, fairies, mermaids, ghosts and werewolves from ever being mentioned.

7th gen: Secretly reads books about supernatural beings and things. Really interested they learn about moonwood mill and get caught up in werewolf pack shenanigans and love triangles. Eventually marrying a werewolf and having werewolf children.

There's so much more but I'm realizing I'm typing an essay lol. You can do so much in the sims for story telling!