React developers have been doing all kinds of side-effects in useEffect() for many years now, and many are in custom hooks or baked into 3rd-party libraries.

React 18 Strict Mode's double-exec will likely cause more problems than it solves, since these are not easy to refactor. https://t.co/b5JTeRWA93

— David K 🎹 (@DavidKPiano) May 8, 2022