This still of programming does not adhere to MVC though, you can't ever swap out the frontend because it's basically merged to the backend and I suspect complex to debug simmilar to JSF.
A different View + ModelView on top of the same Model could then be used to provide a different frontend if that is ever required (in practice, it probably won't be).
Debugging in the frontend is not trivial, but can still be done with the appropriate setting in the properties (https://vaadin.com/docs/latest/flow/configuration/developmen...)