I've tried searching about this and see answers saying that "frequency modulation can be considered as phase modulation" and I do understand that frequency and phase affect each other but why don't stations use direct phase modulation? As in the stations are actually called PM and phase is the variable directly being modulated. Probably there are ways that phase modulation is integrated but I'm kind of looking for a straight up answer that someone not into electronics who is curious why FM and AM stations are the only common radio stations.