Ok, let’s say you selfhost RSS Bridge at myselfhost.net:1234. Let’s say you want to follow a youtube channel, @fancyyoutuber, via RSS. Plug the channel into rss-bridge, and it outputs an RSS feed at myselfhost.net:1234/feed/youtube/fancyyoutuber/atom.xml (I totally made that link up). You plug that into your RSS reader of choice as the feed source, and, boom, the youtube channel is in your reader.