I don’t get why you’d settle for shitty quality music because it’s “just personal.” Your ears. Audacity isn’t the only way to take songs from Spotify. But removing the DRM isn’t possible, so you have to basically re-encode it and that means quality loss.
You can try: muconvert.com/how-to/remove-drm-from-spotify/ or just search for “remove DRM from Spotify”. Plenty of options. But all involve a loopback and basic re-encode to strip the DRM. That means quality loss.
macOS has an app called Loopback that can basically allow you to intercept and route any audio and then capture it. The UI helps see what’s possible. rogueamoeba.com/loopback/