[v0idzer0]

It does, but it runs on more than just unmount when the dependency array is not empty. It runs anytime any dependency in the array changes. This is an important distinction. For example, event listeners added in useEffect will be removed anytime a dependency changes. Then a re-render will occur and they will be added back in the next useEffect body execution. This differs from componentDidUnmount which obviously only runs on unmount and never in the render cycle