This was more explicit when implementing class based components than functional components because the class based API had explicit overridable methods for those aspects of the component lifecycle.
That issue probably wouldn’t exist except that React has to make some concessions to performance, therefore component reuse, therefore component state working in sometimes unintuitive ways.
That issue probably wouldn’t exist except that React has to make some concessions to performance, therefore component reuse, therefore component state working in sometimes unintuitive ways.