Well because its decoupled from light itself or its properties.
If there’s some universal limit for causality itself, then light just happens to be the fastest thing among all the other things subject to causality.
If there’s some universal limit for causality itself, then light just happens to be the fastest thing among all the other things subject to causality.
Other similar particles, like the W and Z bosons, are manifestations of the weak field. Since that field breaks the symmetry, those particles have mass and move slower.
BTW, that symmetry breaking is the very same one that physicists talk about when we discuss the Higgs boson.