In the second video, the narrator describes 'gravitational lensing' which immediately came to my mind before he mentioned it. We only observe the effect of gravitational lensing when light passes around some massive body in a geodesic path. If light caused gravitation we should observe the lensing effect through all of the space traversed by the light beam, since the light beam would be the cause of the spatial dimension warpage.

Additionally, 'time' is not a thing in itself; therefore it cannot be the cause of any effect. Time is just another word for duration (the duration between or among events). And how do we measure any given duration? From other 'shorter' durations (think, how do we measure an hour? From minutes, and how do we measure minutes? From seconds, etc.). This process must continue with a limit of 0 duration (or if quantized, some ultimately short duration which cannot be measured by a 'shorter' duration). In either case, 'time' evaporates into something which cannot be objectively measured; therefore not a 'thing' and therefore unable to effect a cause for something like gravity.