https://www.bbc.com/news - no feeds detected, the addon doesn't find rss feeds on some webpages having them. You have to add those feeds manually. But Simple Rss plugin is the best of all existing for Firefox 64+. Author of the addon, please exchange windows positions in sidebar: move rss list to the bottom and rss content to the top and make the windows resizable.

So nice - so simple.
As to the points the last commenter made It's very much subjective (no disrespect).
Install the add-on, add the bookmark of feed page to simple feeds folder and that's it. The feed headlines are updated when the feed page is, and past headlines are gone. Didn't read the feeds before the page was updated - miss that day(s). A simple scroll through a list and one recognises past headlines.
If you have to know all and every feed headline, this is not for you, but if you are someone who feels they are drowning in information, with hundreds of headlines demanding your attention, you may well like this.