I suppose you have a class of data that is not trivial enough to store in a single component's state, but also not worth sending to the server. Personally, I'm happy to be rid of having to maintain this kind of state if I can.
> I suppose you have a class of data that is not trivial enough to store in a single component's state, but also not worth sending to the server.
Exactly. For example, one application I'm working on has a complicated multi-page form/wizard. Redux is great for keeping this manageable and in fact takes care of all the management for this without me also having to write code for managing it on the backend at all.