Complexity is a very real and objective thing. When you can't 100% guarantee your program won't go into an infinite loop when you change a single line, it's too complex.
Have you done a lot of work with Hooks and useEffect? React changed the entire component lifecycle with the introduction of hooks. All sorts of weird things trigger re-renders now, including when a dependent function changes. You have to surround all of those with useCallback.
I should do a thorough writeup of the infinite loop issue in React.
