If we keep that in (https://codesandbox.io/s/93yv4j129p), my previous comment holds true: https://news.ycombinator.com/item?id=19332577
Here is by the way a version with all artificial slowness removed: https://codesandbox.io/s/9859x0wm9p You can see that this example does not need any optimizations out of the box. This is why I added the slowness to simulate a more complex app.