The reason for this is that they lived in a region abundant in wood and other materials that were more suitable for crafting containers and tools. They were skilled at basketry, using cedar bark, roots, and grasses to create intricate and durable baskets for storing food, carrying water, and other purposes. They also used wood for carving bowls, boxes, and other vessels.
While they didn't make pottery themselves, they would have traded with other tribes who did. However, there's no strong evidence suggesting pottery played a significant role in their daily lives.