Imagine that you have just started to use Excel or Photoshop. Both of those apps have an insane amount of functionality, and it would be unreasonable to expect the user to understand what is possible and how to do it immediately. Over time, with continued User Involvement, they will simply grow more comfortable with the app.
User goals change over time. Help the user to recognize situations for functionality usage so they are able to use those situations as opportunities to improve their skills. This makes improving user skills a meaningful activity. The most successful app adoptions come from a project
This is a major reason for the importance of Continuous onboarding: if people’s skill grows over time, why would we assume that only teaching users about how the app works near the beginning of their experience is at all effective?