Good point OP. It's another part of the game that's been ignored as time goes on. :/
I would love Elder-only reward traits (my signature has a link to a thread about that) which unlock based on how your Sim lived their life up to that point.
It would be fun if maxing a skill got you a reward trait related to it. Especially if these were based on the idea your Sim had a "reputation" for being great at certain skills. You could choose a helpful trait and a more devious trait for each skill. Some examples:
Level 10 Programming: That Techy Friend, where Sims will ask you to fix their tech for them but you get a monetary reward and relationship boost for doing it, or Hacker, where evil Sims can ask you to hack their enemies, risking a relationship nosedive and fine if you get caught, but big-time Simoleons if you are successful.
Level 10 Charisma: Advocate, where your winning smile and charm can convince Sims to do things for others, or Manipulative, where your knowledge of human psychology gets people to do things for you.
Level 10 Parenting: Mentor, where you are so well-known in your community for helping kids that you have a huge boost to your ability to influence young Sims' Character Values even if they're not in your family, or Bad Influence, where you've grown tired of bringing up the promising youths of tomorrow and would rather encourage rebellion and watch the world burn.
Level 10 Singing: Star, where you are so recognised for your Singing talent that others are excited to meet you and may request songs (for a relationship boost or even as a commission), or Diva, where your renowned talent gives you more selfish whims and makes it easier to intimidate other Sims into doing something for you.
