I don't know that I'd call it a mental construct, so much as an effect, like temperature, pressure, color and sound. Frequencies and amplitudes. Time is frequency, events are amplitude.

Our bodies and emotions are largely evolved in terms of pressure and temperature, but we have some mental distance from them. It's our mental function that is a consequence of change/time.

Though we try to apply the individual experience of a singular sequence to the entire universe, because human culture is about everyone following the same narrative, adhering to the same rules, using the same measures, so the idea all clocks should beat at the same rate seems natural and argue it can only be the curvature of spacetime that would cause them to run at different rates, but the simple fact they are separate actions is the real reason. Think metabolism.

The tendency is to either synchronize, which is effectively centripetal, or harmonize, which is effectively centrifugal. So the nodes pull together and function as one, while the networks spread out and fill all the niches and spaces, with each operating at distinct but collaborative rates. Organisms and ecosystems. Particles and fields.