Sims actually do interact better/worse with other sims based on traits and moods - with one issue: Sims default to a generic "Chat" interaction when you aren't guiding the conversation.
This means that directing the conversation has varying results (positive or negative) whereas letting them interact autonomously defaults to inoffensive chit-chat unless one or both sims are in a bad mood, flirty mood, angry mood etc.
There are mods available that remove this generic chat and make conversations more meaningful and interesting, allowing sims personalities to mesh or conflict more.
