Of course relativity also complicates things with time as well. Whose second? Even if you have two different caesium-133 atoms monitored, one on earth and one on a satellite they won't rise at the same rate although both are defined the same.
I guess the real "illusion" would be that if there is truly nothing to be a frame of reference there is nothing for time to "flow" relative to.
I guess the real "illusion" would be that if there is truly nothing to be a frame of reference there is nothing for time to "flow" relative to.