Here's why:

* Rigid Structure: The cell wall is a tough, rigid outer layer that provides structural support and protection. It's made primarily of cellulose, a complex carbohydrate.

* Shape Maintenance: The cell wall helps maintain the shape of the plant cell, allowing it to withstand internal pressure from water and maintain its form.

* Protection: The cell wall acts as a barrier against external threats, such as pathogens and mechanical damage.

While other parts of the plant cell are important, the cell wall is the primary structure responsible for providing support.