8Theme uses this attribute because it is the easiest way to add both developers and ordinary users. While the picture element provides the user with a more extensive set of options to WordPress themes, we decided that we attribute srcset more convenient as a turnkey solution. In addition, it will fit in if switching solutions for you goes beyond Art Direction purposes.
Currently, RICG Responsive Images adds the attribute sizes for completeness attribute srcset. The reason is that initially developers realized that couldn’t predict what might these dimensions, because they depend on how the user styled theme.
8Theme continues to work on this problem and encourage users to include their own attribute sizes to our premium WordPress themes - either manually or using the plugin in WordPress themes, such as wp-“lazy-sizes”. It should also say that the specification adaptive image was recently changed, and use the handle w must now be accompanied by an attribute sizes. The exception attribute sizes make markup technically incorrect, while the rollback will continue to be the standard size of 100vh.