The mundane answer to the philosophical question is that the frequency domain is not any less or more "real" than the time domain; they're different mathematica

The mundane answer to the philosophical question is that the frequency domain is not any less or more "real" than the time domain; they're different mathematical abstractions of change. Just like base-10 numbers are not any more or less "real" than base-2 or base-8. Carthesian coordinate locations are not any more or less "real" than polar coordinate locations. Some representations are just more convenient for specific calculations than others (mostly by simplifying specific calculations).