In between recitals is a time for experimenting with music and collaborations. Choosing what you would like to play, working with others, building foundations. But twice a year lessons are focused on the performance pieces, and that shifts the entire energy and focus of practice.
Recitals are a motivation to really put in the practice hours. To perform something harder than your normal pieces, something that takes months to learn instead of something you can learn in a week. After a recital these pieces and performances take students to another level. These more challenging pieces have the added benefit of being more fun to play, once you get past the difficulty barrier and learn the piece. I hear way too often from parents that they are so tired of hearing the recital pieces because their child LOVES to play them and never stops!
I always say that this is the real test of whether or not your child likes to play their instrument. It's not whether or not they want to practice (because no one really wants to do that!), but when they learn a piece that they really like do they find joy in playing it over and over again? If so you definitely have a musician on your hands!