It was only a small step from the big background images trend to the big background videos one, and it appears that this too has become a thing. And it isn’t bad at all, if it is done properly and the video isn’t large enough to crash the users’ browsers. The best thing about it is that it makes sliders useless, not that they weren’t already, but now there’s another reason for not using a slider. However, this doesn’t mean big background videos should be used everywhere you normally had a slider. There’s a time and a place for using either of them, and must be carefully picked in order to make the website efficient and presentable.