From a theoretical point of view you can see this as the fact that the 3 standard model interactions are forces (they generate 1D displacements), while in general relativity gravity exerts deformations* (which are described roughly as 2D displacements).

1D displacements are described by vectors (i.e. spin-1 objects) while deformations are described by particular rank-2 tensors (i.e. spin-2 objects). This is the reason.

Why gravity does exerts those deformations instead of forces and is so different is yet to discover.

*Deformations are intended, roughly, as the application of force in 2 different directions, usually not collinear

From a theoretical point of view you can see this as the fact that the 3 standard model interactions are forces (they generate 1D displacements), while in general relativity gravity exerts deformations* (which are described roughly as 2D displacements).

1D displacements are described by vectors (i.e. spin-1 objects) while deformations are described by particular rank-2 tensors (i.e. spin-2 objects). This is the reason.

Why gravity does exerts those deformations instead of forces and is so different is yet to discover.

*Deformations are intended, roughly, as the application of force in 2 different directions, usually not collinear, so that it deforms the path and shape of objects immersed in the gravitational field

From a theoretical point of view you can see this as the fact that the 3 standard model interactions are forces (they generate 1D displacements), while in general relativity gravity exerts deformations (which are described roughly as 2D displacements).

1D displacements are described by vectors (i.e. spin-1 objects) while deformations are described by particular rank-2 tensors (i.e. spin-2 objects). This is the reason.

Why gravity does exerts those deformations instead of forces and is so different is yet to discover.

From a theoretical point of view you can see this as the fact that the 3 standard model interactions are forces (they generate 1D displacements), while in general relativity gravity exerts deformations* (which are described roughly as 2D displacements).

1D displacements are described by vectors (i.e. spin-1 objects) while deformations are described by particular rank-2 tensors (i.e. spin-2 objects). This is the reason.

Why gravity does exerts those deformations instead of forces and is so different is yet to discover.

*Deformations are intended, roughly, as the application of force in 2 different directions, usually not collinear