That is the least arbitrary unit system. It’s the only unit that actually matters. Meters are arbitrary, in that it’s a number chosen to be useful to humans. The speed of light isn’t. It’s a measurement of a natural phenomenon, which we didn’t decide. (arguably, the time measurement is arbitrary though.)
The choice to fixate on it is arbitrary, though. That the math is easier when C=1 doesn’t really mean that C is 1 any more than it is 299,792,458. C is C. The 1 is convenient.
In many advanced physics fields, they use an arbitrary unit system in which c=1, making equations easier to write down. E=m
That is the least arbitrary unit system. It’s the only unit that actually matters. Meters are arbitrary, in that it’s a number chosen to be useful to humans. The speed of light isn’t. It’s a measurement of a natural phenomenon, which we didn’t decide. (arguably, the time measurement is arbitrary though.)
The choice to fixate on it is arbitrary, though. That the math is easier when C=1 doesn’t really mean that C is 1 any more than it is 299,792,458. C is C. The 1 is convenient.