According to the prevailing scientific understanding, spacetime is indeed a fundamental concept that underlies our understanding of the universe. It is the fabric in which all physical phenomena occur, including the motion of objects and the propagation of light.
In the theory of general relativity, formulated by Albert Einstein, spacetime is described as a four-dimensional manifold that can be curved and distorted by the presence of mass and energy. This curvature of spacetime is what we commonly refer to as gravity. Massive objects, such as stars and planets, create a "warping" effect on the surrounding spacetime, causing other objects to follow curved paths in their vicinity.
However, it's important to note that the extent of spacetime's warping or curvature depends on the distribution of mass and energy in the universe. At small scales, such as the Planck scale (around 10^-35 meters), our current understanding of physics breaks down, and we don't yet have a complete theory that describes the behavior of spacetime in these extreme conditions. The effects of gravity and spacetime curvature are most prominent in regions with a significant concentration of mass and energy, such as around black holes or during cosmic phenomena like neutron star collisions.
Beyond the Planck scale, where quantum effects are expected to dominate, our current understanding is limited, and we need a theory of quantum gravity to fully comprehend the nature of spacetime. Various theories, such as string theory and loop quantum gravity, aim to describe spacetime on these tiny scales and potentially reconcile quantum mechanics with general relativity.
In summary, while spacetime is believed to exist and can be warped by the presence of mass and energy, the extent of its warping depends on the distribution of these factors. Our understanding of spacetime is most well-developed in the macroscopic regime and breaks down at extremely small scales, where a theory of quantum gravity is needed to fully grasp the nature of spacetime.