From the article’s intro:
The open web’s success is built on interoperable technologies. The ability to control animation now exists alongside important features such as zooming content, installing extensions, enabling high contrast display, loading custom stylesheets, or disabling JavaScript.
Sites all too often inundate their audiences with automatically playing, battery-draining, resource-hogging animations. The need for people being able to take back control of animations might be more prevalent than you may initially think.
Basically (for the tech):
@media screen and (prefers-reduced-motion: reduce) { }
@media screen and (prefers-reduced-motion) { }