> but you'll excuse me being skeptical that introducing more complex tools will solve my complexity problem

I'm a consultant and in my experience this misconception is by far the most common source of problems in redux projects. Redux is a very small and simple thing so you have to build a framework around it. Even redux-thunk isn't enough - that's only 5 lines of code.

I wouldn't recommend react/redux for public facing sites if there's no experienced, pure frontend team. A more batteries-included kind of framework would be better. There's a lot of thinking to do and hardcore levels of scaffolding to maintain before writing anything useful and maintainable with redux. But it can absolutely lead to maintainable applications.

Also, I've never seen any homegrown "vanilla" frameworks or data stores work well as complexity increases. It usually ends up as spaghetti, especially with a growing team + growing business demands. Or best case a poor re-invention of the wheel. There must be brilliant counter examples but they're probably rare, I may never have the pleasure of working with one.

Because I decided I like React? :P

From my perspective, React is the thing with the problem: it doesn't have great state management for complex tasks / multi-component coordination. What I want to use is something like RxJS to manage such interactions and state, because it gives me a lot of power/control in a relatively easy way. One of the best options out there that I've seen is redux-observable, and thus Redux itself is just the "stuff inside the oreo" gluing React to all my interesting "epics" describing high level functionality in the applications.

It's also the Unix philosophy thing of use tools that "do one thing well" and then chain them together. React does view components rather well, Redux does state management rather well, Redux-Observable does state "interaction" rather well. Chained together they work remarkably well.

The problem that you end up with past a certain scale in a component-based app without a state management framework (third party or your own) is that you're performing business logic inside view components. By moving your business logic into your state management framework and using something like redux-saga that is designed specifically for managing complex asynchronous workflows, you can extract your application code from your views and make your views pure functions of the state tree.

When I hear someone complaining about redux using global state, I like to ask them what makes global state bad. The answer is usually that it allows any part of the application to change a value, which makes debugging difficult. This doesn't apply to redux and similar frameworks because every slice of the state can only be managed by a single, pure function, which makes it incredibly easy to debug. Additionally, redux uses a copy on write mechanism, so your state tree isn't actually being mutated, which allows you to use equality comparison instead of a deep compare to see what state has changed. That, combined with the fact that all actions go through a central dispatcher that is easily audited means unit testing your state transitions is almost laughably trivial. And since you are pulling all of your business logic out of your UI components, you can avoid the side-effect hell of unit testing your UI.

Having said that, I won't use react or redux for any website that doesn't have a heavily interactive UI with complex state that must be shared across many pages. Managing application state in your front end is an enormous burden and you'd be crazy to take it on without a need for it.