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.