The main target of the Godot Engine are game developers. But Godot's easy workflow and functional UI elements, makes it also a good fit for non-game applications. There are already some out there you may know, like Pixelorama, an Open Source 2D sprite editor.
I guess it’s more likely to have “decentralized” code using Godot to build an app because of how it’s used in game dev. But that’s seen a lot in web dev too. You might have a react component handle state and children components with their own logic. Sometimes those components are “pure” and only deal with data given to it, sometimes they’re “stateful” and you end up needing to pass data up to the parent.
With proper planning, one could probably avoid mixing up what parts of the app should be pure/stateful.