In Watership Down, "arts and culture" mostly means "telling stories about El-ahrairah," with a side order of games like "bob-stones." We don't see a lot of "bob-stones," but we see lots of storytelling. Telling stories about El-ahrairah does lots of things. For one thing, it bonds the rabbits into a community. But perhaps even more importantly, it holds up El-ahrairah as a model inspires rabbits in times of trouble. In doing so, the stories tell us what the rabbits value.
Cowslip's warren shows us that gaining new arts always involves losing others. Tough luck.
Storytelling is a way for rabbits to remember the lessons of the past in a fun, exciting form. In other words, storytelling is Shmoop for rabbits.