Spotify is not a public service, it is a company. They can pay for user testing in order to improve their product or they can use completely anonymous data. Your privacy is not a necessary sacrifice for products to improve nor should it be.
That being said, I find it OK for them to block users who try to get a paid service, for free. What isn't OK is the advertisement model. A better model in my eyes would be for limiting the free element of the service more and/or running unintrusive ads for the service itself. That way you could still push for more paying customers, without sacrificing the users who can't afford the product.
I do think their is a nuance between tracking how you use the app and letting third party systems track what you do, where you are, etc. Still, they are just a company, not a basic human need.
That being said, I find it OK for them to block users who try to get a paid service, for free. What isn't OK is the advertisement model. A better model in my eyes would be for limiting the free element of the service more and/or running unintrusive ads for the service itself. That way you could still push for more paying customers, without sacrificing the users who can't afford the product.
I do think their is a nuance between tracking how you use the app and letting third party systems track what you do, where you are, etc. Still, they are just a company, not a basic human need.