Well, yeah, it is tautological. If there weren't a limit on the rate of information transfer, everything possible would happen instantaneously and there would be no way to really experience anything. Call it selection bias if you like. The speed of light is like the rate of time; it is because it can't not be in any meaningful way.

This isn't to say that, given the tenets of simulationism, we can't hypothesize an "external time", and describe the rate of our universe as some amount of Tx/t. But the fact that that's an amount of time per time should also demonstrate why it's a meaningless concept in-universe.