This may be because most feed readers don't have a proper way to triage items. Adding a feed doesn't mean you want to read everything from said feed. Usually only a subset of articles are interesting.
I built a feed reader with that concept in mind, having a separate triage stage where you only decide if it's worth reading or not. This will make it easier to handle large feed lists and find the best articles from them.
> So, I looked for them as well but few websites have them.
Many sites have rss, it‘s just not advertised as much as it was some years ago.
I built a feed finder tool that goes far beyond rss autodiscover, it might be useful: https://lighthouseapp.io/tools/feed-finder
I'm just realizing how much we depend on Cloudflare working. Every service I use is unreachable. Even worse than last time. It's almost impossible to do any work atm.
It's an RSS feed reader, and there's a browser extension with which you can add articles to your library directly. You can of course also add articles manually in the web UI.
If I understood you correctly this may be what you're looking for.
A bunch of alternatives were already mentioned. If you’re looking for an rss feed reader that can also save links directly, Lighthouse[1] may be an option.
RSS readers show content based on the feed they're coming from, and show read and unread items in the same list. That makes it difficult to know which items you've already seen, and is especially annoying for managing items that you want to read at some point but not anytime soon.
Lighthouse splits it into Inbox (new items) and Library (bookmarked items). This makes it possible to process new items quickly, and take your time with reading them.