Neither is better then the other. the biggest issues is what format will either play here Mac’s seem to lag slightly behind, being tied to Apple’s software.
It boils down to what are you comfortable using and what level of quality do you want. AFF (apple Lossless) for Apple, FLAC-WAV-ECT for PC ( that’s not getting into the High rez formats). there is a better potential ability of a PC to play the higher Rez Files then Apple. But in the end its what more people have already used and are familiar with.
NAS and a dedicated Streamer-Player is always going to be better then Computer due to all the noise a computer makes in its power supplies.
Don't even consider using the internal sound card. get a outboard DAC minimal. You don't have to go expencive here something like an Audioquest dragonfly ($150-$300) is a substantial step up from most if not all internal sound cards. Better yet get a DAC that runs off a separate power supply Shiit audio comes to mind there for a good starting point.