[kalkut]

As someone one who rewrote a React/Redux project with bare React : Everything in your post is true, I made the same observations and I reached the same conclusions.

Right now with a few devs it is going very well but I do worry about on-boarding people who are not proficient in functional programming.

React code without a global state management library is very pleasant and easy to read/understand for many, but for some it is not always obvious to write. You may have to spend more time code reviewing and training newcomers who will sometimes feel like their task is impossible without Redux. I have yet to see if those requirements can still hold for a big team but I think it is possible.

My current opinion on Redux is that it is best suited for existing project migrating to React because you may inherit very odd relationships between the view and the data and Redux will avoid you a lot of pain on this regard. A new project should avoid Redux & co as long as it can.