In this context threading is less about making maximum use of multiple cores and more about &quot;never blocking the main&#x2F;UI thread&quot;. Even on a single core device you usually need to start offloading heavy computation to a background thread to keep the UI responsive.<p>Even today I&#x27;ll run into websites that lock up a browser tab because they&#x27;re running a whole mess of Javascript soup (typically jQuery). I know we were promised WebWorkers like 5 years ago but does anyone actually use them?