@D4N43 so are you saying that Chise and Elias coming out of their comfort zone, making new friends and relationship is uneccessary? This college is a very important part of Chise and Elias's growth, both about knowledge and emotional.
No matter how nice and vast of knowledge a person is, there is only so much one can learn from just 2 people. Just like how there is just so much Chise can teach Elias about human (and she doesn't understand them that much at that), there is just so much Elias can tell Chise about this underground world. Like these families' affairs, even if Elias knew about them, hearing the stories from people inside makes a huge difference.
Also, let me remind you that before the college arc, Chise only had 2 female friends around her age, and no male friends. All the male she has known until that point are, despite their appearance, a bunch of old men. But here, for the first time ever, Chise has both male and female friends, a group of close friends, and she made these relationship on her own effort at that. And let's not forget this is her first proper experience as a student, something she didn't have before.
The same goes for Elias. Not just his circle of, well, people he knows, expands, he also made a friend, by himself, for the very first time in his life. Up until now, all the "friends" Elias has are people who approached him first, not vice versa, and he was pretty reluctant, too, despite his interests in human and their relationship. But now, we see that he has been more active in approaching others, making connections and learning from them.
And it's not like this does not affect Elias and Chise's relationship. By getting to know more people, they, in return, also learn more about themselves and are growing, which in turn give them a chance to have a look to their relationship from a different perspective and improve it.