It's not a Medium requirement. I've published plenty of articles without images, and the site just adds a blank box as a placeholder. However, a lot of 'become

It's not a Medium requirement. I've published plenty of articles without images, and the site just adds a blank box as a placeholder. However, a lot of 'become popular on Medium' guides recommend you use an image, and an image likely looks better than a blank box does, hence all the images.