You could in theory do that although the experience would be slightly odd. Either open the video in a new page and put in the bottom right, force focus it after the main window been active. Or wrap the entire websites in two iframes, one for main content and one for video player. Main content can change without interfering with the video player.

Not saying you should do either of these, as the UX would be worse, but you could if you really want to :)

That s super annoying btw . Frankly video is best browsed like a traditional multi page listing, like how porn sites do it

This is such an interesting inversion. IIRC, one of the original arguments for SPAs was that they would be so much quicker than MPAs because they don't reload the entire page on every action. Now it seems like we've come full circle and SPAs are considered to be done well when they can achieve the speed and feel of an MPA!