The biggest issue is that for the first few years there was no single standardized way to write Redux code. Everyone came up with their own patterns, and wrote their own helper libraries. It also required a lot of "boilerplate" code for things like defining action type strings, action creator functions, and hand-written immutable updates.
That's why we published our official Redux Toolkit package in 2019. It standardizes Redux usage, and includes methods that build in our recommended approaches for things like store setup, writing reducers, simpler immutable updates with Immer, and even a complete server data fetching and caching solution called RTK Query:
- https://redux.js.org/introduction/why-rtk-is-redux-today
- https://redux.js.org/tutorials/essentials/part-2-app-structu...
We routinely get highly positive feedback from folks who hated writing old-style Redux, but love using RTK.
Related, we also have a "Style Guide" docs page that provides guidance on what approaches we recommend using when writing Redux code: