Here's why:

* It describes a fundamental relationship: This law states that every particle in the universe attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This describes a fundamental force of nature.

* It is universally applicable: This law applies to all objects, from tiny atoms to massive planets. It's not limited to specific situations or conditions.

* It is quantitative: The law can be expressed mathematically, allowing for precise calculations and predictions. You can use the equation to calculate the gravitational force between any two objects.

* It has been repeatedly verified: Numerous experiments and observations throughout history have confirmed the validity of this law, making it one of the most reliable and fundamental principles in physics.

While scientific laws can be refined or modified with new discoveries, they represent well-established, fundamental relationships in the natural world.