Text-based browsers like ELinks, Lynx, and w3m struggle with modern HTML features. While they handle basic HTML well, recent additions like disclosure widgets, dialogs, popovers, and the inert attribute are either ignored or improperly rendered. The most problematic issue is the complete lack of support for the hidden attribute, causing hidden content to display visibly. This creates challenges for progressive enhancement techniques that rely on hiding content in HTML before revealing it with CSS or JavaScript. The gap between text-based browsers and modern web standards continues to widen.