What is the video equivalent of vector graphics?
The whole premise of vector graphics is that there is a drawing engine in the output device that can interpret graphical commands and output shapes and fonts at the maximum resolution of its rasterizer.
In simple terms, when someone produces a Postscript projector or media player, there will be a video equivalent of vector graphics.
But in another sense, this is already the case with video production software that lets you create titles and graphics using TrueType fonts and vector drawing tools. The renderer, such as the Media Export engine in Premiere Pro, rasterizes fonts and shapes at the maximum resolution of the output video format. You don't have to worry about pixelated graphics and fonts that would result from importing low- resolution artwork. This video rendering of vector sources is equivalent to the work of a RIP (raster image processor) or web browser, which render PostScript (vectors and fonts) at the maximum resolution of an imagesetter or printer for output on film or paper or a webpage.
Ultimately, shapes, images and text all have to be turned into dots/pixels at output time. All output devices -- with the exception of pen plotters -- can only print/display dots/pixels -- solid spots of a single color. That applies to laser and inkjet printers, computer monitors and TVs, digital platemakers, and even crowds of people holding up colored cards to make gigantic pictures in the stands of football stadiums.