SM has so much fun and upbeat catchy music. XY, SWSH, and SV sound more "serious" in comparison which makes them less fun to listen too. They still have some stand-out tracks though like some of the toby music from the two latter games and XY's overworld music. SM probably prioritized having a funner sound becsuse it fits its atmosphere
soundtracks aside...SM/USUM and Legends Arceus are the only good 3d games period so far