[ummonk]

Fundamentally, UI is nested. The framework has to reflect this and make UI components composable in a bested way or you’ll drive developers crazy.

What I do wonder about is being able to use a data oriented system that does reflect this neat ability. E.g. if the data in an ECS system is viewed as a simplified relational database, what would happen if we replaced it with a simplified graph database?

[nine_k]

Isn't a graph of objects a simplified graph database?

Trees are not arbitrary graphs; a tree-based database may have nicer propertied than a web of objects, while allowing to describe nesting in a natural way.