It was pretty easy to group unrelated code into a seperate function either in the class or in a seperate module. Every beginner programmer can do that. To write a hook is much more complicated.

Dan is very smart, also redux was very smart but ended being an overkill. Side effects are a concept only thought at the Uni.

That's the core of the issue, useEffect is too complicated. As well as Saga. Even for simple requests it can become tricky to figure out what the flow is.