I'd guess comments like this come from people thinking the primary complexity of Redux is the data store, rather than the "all changes to your state are represented as plain objects". The Redux FAQ goes into this: https://redux.js.org/faq/general#when-should-i-use-redux
Can't blame them missing the forest for the trees when you spend all your time writing the reducers and connectors vs the actions themselves.
Note that our new official Redux Toolkit package [0] simplifies most Redux use cases and logic, including eliminating the need to write action creators and action types by hand and allowing "mutating" immutable update logic in reducers. The React-Redux hooks API [1] is also generally simpler to use than `connect`. We're now recommending that people use RTK as the default approach for Redux apps [2], and I'm working on a new set of tutorials that will teach RTK and React-Redux hooks as the standard approach [3].
Can't blame them missing the forest for the trees when you spend all your time writing the reducers and connectors vs the actions themselves.