I don’t know what 75 kbps opus sounds like, but I can tell you how 32 kbps sounds. Versus mp3 at that bitrate, it sounds actually listenable, while mp3 sounds like you’re underwater.
All things considered, the Spotify songs probably sound fine at 75.
I can only speak to what a 75kbps mp3 sounds like, but unless Opus is like 3x+ better at compression, it’s going to sound like complete dogshit.
I don’t know what 75 kbps opus sounds like, but I can tell you how 32 kbps sounds. Versus mp3 at that bitrate, it sounds actually listenable, while mp3 sounds like you’re underwater.
All things considered, the Spotify songs probably sound fine at 75.