That's a different argument and more about Apple Maps, Mail, etc being the "default app" (which is an option on macOS). That's something I'd like to have, but like I said I don't have a strong legal/moral opinion either way.

They're talking about the lock-in of the App Store and competing with Apple Music. Your argument sounds more applicable to music purchases than a subscription service. Especially with a subscription, it seems more similar to the independent butcher/bread maker competing with a grocery store analogy brought up elsewhere in this thread.

I'm a bit lost on the house analogy and how that applies to Spotify and Apple Music.