In reality we don't really see much of what goes on outside of the trio, and we know Hermione sure as shit wasn't just sitting around gossiping and sipping pumpkin juice.
Snape's not a great example, but he was spending his free time (at least part of it) developing better ways to brew potions and inventing spells.
From what we know of Lily she was pretty similar to Hermione in that she was really engaged with all the magic stuff.
Maybe the good students just weren't the interesting ones because, no matter how cool the magic, doing it in the confines of the classroom or workshopping new spells in their free time doesn't sell the action and the drama.
I'm sorry but, I have never been as excited about ML as I am at the thought of being capable of literal magic. You give me Harry Potter world magic, a wand, and a room of requirement and I'll be damned if anyone sees me for years.