> a Redux action, which would update the global Redux store, which would cause all Redux-connected components on the page to update, which would cause all their children to update as well. In other words, collapsing one comment triggered an update for nearly every React component on the page. No amount of caching, DOM-diffing, or shouldComponentUpdate can save you from this amount of waste.

yeah this is pretty much 1. an incorrect implementation and/or 2. an incorrect take

and easily solvable with a bit of 'render auditing' / debugging