On fiverr you can buy quite decent illustrations from $5 and up. It would work well for so many scientific articles. I bet their readers would appreciate great articles like this accompanied by drawings and other illustrations instead of just text and numbers and primitive graphs like here. Researchers often work in teams for years or months costing hundreds of thousands or millions in equipment and salaries. A few hundred bucks would make their work much more interesting and accessible. I wonder how many more would actually read the articles if they were illustrated. My guess is a factor 10 or more, even among their peers.
Many universities have news services whose job is to do make popular articles with cool pictures. It's usually not a skill scientists are trained in.