You can have an immediate-mode frontend to retained-mode state; see React, Compose, SwiftUI, etc. In this case, the retained state is an implementation detail,

You can have an immediate-mode frontend to retained-mode state; see React, Compose, SwiftUI, etc. In this case, the retained state is an implementation detail, but the goal of the framework is to render your UI function deterministically whether it's updating or creating fresh state.