Why do you think the mandala plays such a starring role in buddhist art?

Mandalas may exemplify the non-possession buddhist tradition

Explanation:

There are multiple possible answers and im afarid im no expert nor in buddhism or mandalas, but as you may also know, im certain that mandalas are well made representations of various (mostly religious) things in sand.

Making a sand mandala may take many hours and effort, and once you are finished, you must erase and destroy it all. I think the mandalas well exemplify one of the four noble truths: Being able to let go.

The third noble truth: "It`s possible to end suffering by giving up attachments (clinging) and expectations (grasping)"

you so ! < 3