I remember stories of how MS skipped Windows 9 because they were worried about a huge number of Apps checking for Windows 95 and Windows 98 by checking for "Windows 9". Are web developers doing something similar tricks when checking the User Agent?
With a greater proliferation of devices than ever before, we developers can no longer rely on viewport size as the factor that determines the styles we serve up to our website users. Up until fairly recently, we might have caught ourselves making assumptions based on the size of a device: that mobile devices would rely on touch input, for instance, while for larger screen sizes we might assume the majority of users would interact with our webpage using a mouse.
The web is single-threaded. This makes it increasingly hard to write smooth and responsive apps. Workers have a bad rep, but can be an important and useful tool in any web developer's toolbelt for these kinds of problems. Let’s get up to speed on Workers on the Web!