[desireco42]

While this is useful to have, I would argue that layout should be left to css frameworks (material css in this case) and components only used for functional parts of the app.

No one is forcing us to make everything a component. What would be a benefit of having a footer or header a component for example?

[Kiro]

If you don't want to make many modifications I prefer having it like this, with each component being completely self-contained with no global CSS dependencies.

[zeroskillz]

Simply for semantics, as they are done with functional components. As far as layouts, you do not have to use them, they are just an added feature to help the prototyping and build phase.