The free tier is what we already have.

Not at all. We hit paywalls, are bombarded with low quality or malicious ads (without adblock) even if we're paying ... it's a mess. Spotify and free streaming platforms keep advertising largely unobtrusive.

In what way? Spotify pauses ads when you mute the volume and resumes them when you turn it back up. Its ads are also louder than the music in general.

The advertising Spotify slots into your playlists is hardly unobtrusive...

Where else would they slot ads? Advertising is obtrusive by default so we have to compare relative to the egregious examples.