I've been using e os every since the fairphone 4 hit the market (and I got it quite fast). I think it's absolutely great. A caveat which is funny to me and I like: Since the playstore service is missing, and micro G sinks every server request to Google, in app purchases via those systems are simply not a thing. Personally I love this si ce I have never needed or want to buy anything from any app; but it's incredible to me that any ad that even tried to load, can't

This is true for the desktop/mobile app application I aggree with you there since its a CEF native on desktop and mobile apps have these kinds of APIs. I very much disagree with the Web client (which admittedly my original comment didn't mention at all, personally I mainly use the Web player)

Since on Web it's just a Website, all previously mentioned serve side tracking applies; but getting any hardware information through the sandboxing would break the browser security model and is not possible since there is no such web API. Web fingerprinting is one of the reasons apple (at least they keep bringing it up as a concern) is not keen on implementing the Web API for the luminance sensor on safari. Interestingly webkit (chromium core) does have the functionality which is why it's behind a dev flag atm (https://developer.mozilla.org/en-US/docs/Web/API/AmbientLightSensor)

Identifying hardware should not be possible according to the browsers security model.

I should've phrased my question as 'what advantage does spotube provide over Spotify premium in the browser', after downloading it and trying it out I am guessing the biggest advantage is the download button and stuff like that? Though... I personally have no use for offline Musik nowadays.

Edit: Sidenote: the Mozilla docs frequently mention that the user agent may be used to infer hardware/browser information, and therefore developers are encouraged so spoof it (and in general not to trust the information given)

Anything you do in the UI has some associated backend request (everything relevant at least). Search queries, loading albums, skipping, changing settings, anything is just a Web requ on their backend server which could still be collected. The custom ui does not save you from relevant data collection. Only thing potentially not getting tracked is empty navigation between tabs, but there is not a lot of info in tab switching

As much as I am a fam of alternative Software and such, what are actual advantages of using spotube over Spotify premium? Disregarding the membership fee.