That would work without OOP. Make a FormRender component that manages that logic (being rendered in a form) and other components, one that manages a keyboard, other that can be clicked and handle hover, touch states, etc.
IMO, the problem is it works really well in so many contexts that people end up trying to use it everywhere.
As to messaging, consider what happens when you add JavaScript that can change the DOM. Now, you need to pass messages in both directions not just What is your Height- Width, but also my Height-Width has changed. Animated Gifs or Videos now want to update things in real time, and other windows can cover parts of your view port.
And let's not forget about transparency.
PS: ECS can still work, but it starts getting really complex.