How helpful is this when you're dealing with a website that does not degrade gracefully and insists using JavaScript to shove things in where a static webpage would work? (For example, scraping football scores from NFL.com)
its not useful in those cases, but usually for those js rendered sites you can replicate the ajax requests which happen and get nicely formed json documents to parse through instead.
Getting this working in a headless browser driven by Selenium would probably be easier for maintainability.