RSS feeds often contain the article text in HTML, and parsing webpages shouldn't be necessary. Kalina, like Newsboat, does support viewing these in terminal—I use Pandoc library to convert HTML to text, links and images are not preserved.

I don't know if fetching webpages and rendering them in terminal is a good idea. You can always use a terminal-based browser like w3m to open them. And I'm afraid most of such pages will be cluttered with animated popups and sidebars, filtering which will require some heuristics. Don't know it's worth it. But this is still something to look into in the future—at the moment there are more urgent things to do in Kalina.