You might not need Redux

It's sad that a post like this is needed... I wouldn't consider doing a modern spa/webapp of even medium complexity without a state machine similar to redux or redux itself. In a team setting it allows you to establish workflows that are consistent and easier to understand.

Also, your reducers and action creators don't need to live together, I tend to import from the base directory into feature based structure/directories. A given directory/feature does not need to contain all of actions(creators), reducers, dumb/smart/pf components and sub-components. But by organizing data/handlers into features and components into features, sometimes in the same directory, it makes it easier to find/discover, though it may seem chaotic at first. Imho, it's better than having to traverse through a deep tree to go from a component to a reducer, etc.

I really like redux, and I'm personally inclined to lean on it, even if it makes the code slightly more complex, that complexity is consistent and easier to follow than just about everything else I've seen.

That said, if you have state that doesn't need to be persisted, then go ahead and keep that at a component level. You can have a higher level component with your actions and setstate, then pass them down to more simple components, or pure view functions.