In my mental model of an offline app, I expect instant responses. However, I know to the complexities of apps, the diverse wants of a big, diverse user base that it can be hard/impossible for an app to be well-architected enough to achieve this ideal.

Failover is hard, and there generally aren't hard rules for what to do if data isn't available or how to communicate to a user in a specific offline situation on how the current state of an offline app affects what they see -- and even when they would care or what they could do about it when they do care