Consider a light bulb, magnetism, ionizing radiation from an isotope, or even sound pressure. When you measure the energy of these phenomenon at multiple distances, the difference in power follows the inverse square law. Also note that photons do not interfere with themselves (except indirectly through their contribution to time dilation which is negligible), but they do interact with other particles transmitting heat, radio waves, energy for photosynthesis, and giving us sunburns.

In the case of gravity (the most commonly observed effect of time dilation), it follows the same inverse square power/distance rate. Now since I mentioned sound pressure as following the same rule, one could simply argue that mechanism (ripples in a medium 'vs' free-radiating energy) justifies the spacetime manifold theory of time dilation.

But there is one significant difference between the free particle-centric and warping mechanisms: Warping is self-interfering. Noise canceling headphones make an attempt to generate a 180-degree out-of-phase copy of ambient sound to cancel it, but there is no such property for photons. If a boat crosses the wake of another, it must traverse those waves increasing distance/effort, but there is no theoretical limit to the quantity of photons that can be in any given space short of exceeding Schwarzschild radius density from the cumulative time dilation contribution of those photons. Photons do not self-interfere.

LIGO is currently searching for evidence that gravity waves interfere with themselves (ripples upon ripples, or spread due to large gravity wells). The spacetime model is the one they proport, however, to date they have no compelling evidence.

https://www.ligo.org/science/Publication-O3aLensing/

I will admit that the observations so far are inconclusive, and they're essentially looking for identical snowflakes in multiple recordings of blizzards. To be sure, LIGO is not sitting perfectly quiet and only disturbed by the collision of neutron stars and black holes. The rotation of the earth, wobble of the moon, and pushing back your dining room chair are all creating vibrations and non-coincident noise that must be computed out. But to this point, the sharpness of results and congruence to distortion-free theoretical models imply that gravitational lensing of gravity is not occurring. And this implies that time dilation (source of gravitational effect) functions like other gauge bosons (photons in particular) where they are not self interfering but may interfere or interact with other types of particles.

The physical properties that I believe are observed in all instances of time-dilation (including special and general relativity computations) is caused by a variation in time dilation particle density pressure in a given area. Imagine instead of a gravity well being a sloped hole, it is a seepage or pipe leak releasing liquid on the surface. It thins as it spreads, but the closer to the "well" or source, the more depth and resistance to movement is experienced.

LIGO detected the change in "depth" caused by frame dragging of two substantial wells (neutron stars) in a moment of rapid oscillation. the brief moments that the masses were moving perpendicularly to us in their rotation, that reduced the amount of time dilation focused towards us, and the moments they were spinning in our direction there was a bow wave accumulation of ‘c’ rate celerity bosons that resulted in a sudden burst. Only that these two massive objects were in an accelerating figure skater spin at a relativistically high velocity before colliding did accumulations and deficits of time dilation become apparent.

This description does not vary significantly from that of a spacetime version, and I constantly consider how that manifold applies to this and other theories. However, I always conclude that the underlying mechanism is more likely particle based or at least a radiative force for a plurality of reasons which include:

-The lack of confirmed gravity lensed gravity waves.

- Sharpness of photons across long distances (deep space star observations).

-Propagation speed of neutrinos.

-Compatibility with quantum mechanics including but not limited to entanglement.

In the same way that relativity matches Newton's computations except for periphery observations where Einstein demonstrated better results, I am confident that a quantum time dilation model like the Celerity Boson I've hypothesized will equal relativity while better describing the new periphery observations of the last 100 years.

That being said, the only wrong approach to science is assuming that any model (existing or proposed) is the unimpeachable answer, or the unwillingness to consider that which proves our scientific beliefs to be incomplete.