Well, okay, but we can map different cause-and-effect relationships to other ones. Like for example, I can say that so many trillions of energy state transitions in a caesium atom will occur in the time in takes me to walk to the park down the street, or drive across the state I live in, and anyone with a caesium atom can, in principle, replicate that measurement. And you can replace the caesium atom with, for example, a spring and some gears, or literally any other periodic event generator. (I mean, we can get into what "periodic" means, as well, but I'll table it for the sake of brevity, for now.)

And, somewhere in our brain, we probably have just such a periodic event generator, although it's probably a bit flawed in the implementation like most things generated by evolution typically are, but it does the job well enough for us to arrive at a sense of time that very roughly agrees with more rigorously-derived measurement devices.

Ultimately time is a shorthand for cause and effect, and the fact that causes propagate to their effects at roughly the same speed (relative to a reference cause and effect) everywhere we measure them (relativistic effects notwithstanding). If you have evidence this is not the case, I would love to see it, because it implies some new physics. You would win a Nobel prize for this, easily, if you could prove it.