The whole point of an agreement is that it sets out what parties will do for each other, and what happens if there is a breach.

Apple could already do things with the App Store without needing to agree to something to get Apple to let Apple do App Store things.

Apple is not going to sue themselves for being in breach.

etc.

Just because there's e.g. a license agreement doesn't mean you need to agree to something, if you are somehow otherwise authorized to do the thing. E.g. fair use, or you have a pre-existing right or ownership, or whatever.