Having a discussion about things you disagree with or seeing opportunities for learning are not the only kinds of good conversations. Just a couple of ideas: Being able to work out thoughts or knowledge together with someone else is nice. A topic you are enthusiastic about is still fun to talk about with someone else enthusiastic. Work-related stuff you maybe want to discuss only with colleagues, because it is too specialized for others to talk meaningful about. And for most human stuff it is easiest to share your worries with a friend who has roughly the same values as you.
Different stuff each other have seen, places we've been, things we've done. If they already share my opinion on everything, I could save a lot of time avoiding things I wouldn't like and probably learn about new things I would like.
