It allows you to temporarily unblock the main thread/renderer before performing a potentially expensive computation. I’ve used this technique (with plain reques

It allows you to temporarily unblock the main thread/renderer before performing a potentially expensive computation. I’ve used this technique (with plain requestIdleCallback) to display incremental UI feedback as a chain of computations progresses. This is in an application I inherited/maintain, with some existing performance problems. I intend to make more substantive performance improvements, but this stopgap measure significantly improves perceived performance, eg by immediately showing the effect of a direct interaction such as a checkbox state change even if the triggered computations may take ~500ms. The downside is it potentially introduces “jank”, where incremental changes render temporarily, and computation time is somewhat slower overall. In my experience/opinion, the tradeoff is worth it around 100-200ms depending on what’s being unblocked.