For most desktop applications, this bottleneck is not that restricting though. Almost any noticeable UI delay is due to stuff that ought to be offloaded into a

For most desktop applications, this bottleneck is not that restricting though. Almost any noticeable UI delay is due to stuff that ought to be offloaded into a background thread, but isn't. For example, IntelliJ often freezes up when I enter a search string in the settings dialog, which is probably due to a search index being loaded or built on the UI thread. Layout engines for browsers do get parallelized though. And the point of modern 3D APIs like Vulkan APIs is precisely to allow calling it from more than one thread.