Quick, pace, speed are some synonyms which describes us. We , humans, wants pace in each and every act of ours. We want to speed up things as much as we can do. So we try experimenting things as in we try to search for betterment of work, as we are growing in automating things, replacing human acts to programs or machinery.
If I talk about selenium, then the major time which is spent in framework is at execution. And if I go one step more deeper then the initial point where the execution takes time is when it is trying to open browser be it Chrome, IE or any other. So just to wipe out this pain point there is one such browser which works in headless mode, and is compatible with selenium as well.