I paid for Spotify directly with a credit card on their website and then logged into my existing account inside the app. So, by definition, I wasn't forced to subscribe through Apple.
It's true that you're not allowed to advertise that you can do this inside the app itself, but that's not the same as saying you're not allowed to do it at all.
It's true that you're not allowed to advertise that you can do this inside the app itself, but that's not the same as saying you're not allowed to do it at all.