I would say there are advantages to having both series and parallel wiring. You can get interesting tones when using more than one coil. When using two coils, they can be combined in series, parallel, humbucking in phase and out of phase. When two coils are hooked up in series you have maximum DC resistance of both coils added together. When in parallel, the total DC resistance is less than either coil individually. When the two coils are hooked up in series you have maximum fullness and output in the pickup. When in parallel you get a nice mid tone out of them. Using a standard 5 way lever switch on a Fender Stratocaster, the 2 & 4 positions put the pickups in parallel with each other. The 2 & 4 positions are often mistakenly called the “out of phase” position. The pickups are connected in parallel and are properly in phase.