Why is Subscription Status in the monetization tab?

When building an application that requires user’s subscription status, You’re required to go through entire onboarding process. It seems like an overkill.

Can anyone elaborate on why is onboarding required?

Afaik, some extensions receive revenue by implementing subscriber only features, which is why you need to go thru onboarding. However, I think this is a closed program, (for ex. only Amazon apps receive revenue)