If you want state management you use a state management library. If you want optimization, you do memo, or pure component. You don't rely on the fact that some state library does that for you. You don't want your component's performance changes drastically when you refactor to context or whatever
> Have you ever dug through a complex heavily nested application trying to debug a performance issue, only to find a custom shouldComponentUpdate method within every individual component?
The author specified a performance issue that they're trying to debug, but in my experience it's just as common to waste cycles debugging a "why is my component not updating" issue, which is the flip side of the coin: not enough re-renders, instead of too many. So the way I see it, it is not a performance problem per se, it's a state management problem; poor performance (from spurious rerenders) is just one of the possible symptoms of immature state management.
