An aside: Why do so many websites (like this one) now have large blank spots near images when browsing with JavaScript disabled? I'm not much of a web develope

An aside: Why do so many websites (like this one) now have large blank spots near images when browsing with JavaScript disabled? I'm not much of a web developer, but it looks like the site was trying to use srcset but used it in a weird way that has two img tags with the srcset of the images, with one with a data URL in the src attribute that contains a blank image and the dimensions of the image. So right next to the image is a large blank spot. It appears that some JavaScript hides one of these images. Similarly, many websites show all sizes of the images when you have JavaScript disabled. As far as I'm aware, it is possible to do responsive images without JavaScript, so I don't get why people do things like this.