It is always the case. Even if you model app state in a functional way, the state is still <i>somewhere</i>, for example a haskell program may be pure but only because it pushed the unsafePerformIO call into the runtime. UIs <i>always</i> have additonal state that is not modeled in the backend, we can only reduce the surface area of code that is stateful, but we can&#x27;t outright remove it, it is essential complexity in all UIs.