Why is the final video rendering of time-lapse photography very slow?

I am a professional video producer, which is related to many factors. It depends on what software you use to render, the format and size of the rendering, and the configuration of the computer. Because rendering is frame by frame, one frame is a picture, and 24 frames is one second. Some algorithms in China are 20 frames per second, and many pictures are connected together to form a video. I often use ae to render 1920 * 60 after special effects. A 5-minute film needs to be rendered for several days, because a second video has hundreds of megabytes or even G, which means that a second video needs to render 24 high-definition pictures, so it is very slow.