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.
The most successful app adoptions come from a project, because they give the user a reason to increase their skills. As they work on their projects, they'll bump up against the boundaries of what they know.
Apps with continued user involvement are responsive to increasing skill levels over time. 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?
User goals change over time, and the app can only keep up with changing user goals if user skill level also increases. Help the user to recognize situations for functionality usage so they are able to use those situations as opportunities to improve their skills.