I feel the way you use the inject decorator in order to pass the state to all of your components is wrong.
The concept of smart/dumb components is important because it allows you to separate the state from your components. this is a a good thing, not a bad thing.
Today you use mobX which allows you to inject your state easily, Yesterday you used redux and tomorrow who knows ?
Keeping the concept of smart/dumb components allows you to migrate easily between different approaches of state handling. If you use inject in all of your components they are tightly coupled with mobX, and not that it’s too difficult to remove these inject decorators from your code but your whole components structure will be harder to maintain.