Meditation is both fundamental and incidental to a Zen practice. Our Buddha Nature is just the same whether we sit with it or not.
If I had the choice of practicing Zen without meditation or practicing meditation without Zen, I would practice meditation.
I like the idea from the Soto school of Zen Buddhism that sitting meditation is enlightenment itself. If you embrace that idea, when you sit, you have nothing to gain or lose, you are simply enlightened. You are there.
Breathing, eating, sleeping, standing, sitting, being kind, developing a compassionate heart from which compassionate actions flow, experiencing your Buddha Nature, and helping others to experience It are all important elements of a Zen practice.
To really understand the importance of meditation, just sit.