While it is true that in the framework of general relativity, gravity is described as the curvature of spacetime rather than a traditional force, the search for a quantum theory of gravity is motivated by the desire to understand how gravity behaves at the quantum level and reconcile it with quantum mechanics.
General relativity provides a remarkable description of gravity on large scales, such as the motion of planets, galaxies, and the overall structure of the universe. However, at extremely small scales, such as those approaching the Planck scale (10^(-35) meters), where quantum effects dominate, the classical description of gravity breaks down.
In the realm of quantum mechanics, the other fundamental forces (electromagnetic, weak, and strong forces) are successfully described by quantum field theories, which treat particles as quanta of their respective fields. Scientists are searching for a quantum theory of gravity to understand the behavior of gravity at the smallest scales and to develop a consistent framework that unifies gravity with the other fundamental forces.
One of the concepts that arises in this quest is the hypothetical particle called the graviton. The graviton is a hypothetical particle associated with the quantized version of the gravitational field. Just as the photon is the quantum of the electromagnetic field, the graviton would be the quantum of the gravitational field if such a particle exists. The graviton is postulated within the framework of quantum field theory to describe how gravity might manifest itself as individual particles.
The search for a quantum theory of gravity, including the investigation of gravitons, is driven by the desire to understand the fundamental nature of gravity at the quantum level and to resolve the theoretical incompatibilities between general relativity and quantum mechanics. It is an active area of research in theoretical physics with the goal of achieving a more complete and unified understanding of the fundamental forces of nature.