I chose to learn React due to both the hype and the fact that we had begun to code React Native at work. It's been a mostly positive experience with some exceptions here and there. I still don't see much of a point in it in small to midsize projects, where speed of development would point me more towards jQuery/Coffeescript spaghetti than a full, modern front-end framework. Reason being, the most important aspect of early development on these projects is speed of iteration. Everything else comes second, including how reactive the front-end is. But React seems like a nice way to organize 1) massive front-end projects, where organizing into a lot of small components makes the project much cleaner, and 2) one-off components when traditional rendering becomes too slow during scaling. In the case of the former, my logical next step was to pair a Rails api-only app with a React frontend, and add user authentication.
react-rails-auth is a fully dockerized repo that contains the app I coded to learn React and Redux. It's meant to be as unopinionated as possible so that I (and you!) can use it as a starter for any future projects in react/rails.