As long as those sources have an RSS feed (that is usable, looking at you Medium), sure. But, most sources that _most_ people (not geeks) like... don't.
The comment above where someone said "RSS isn't dead, I have a business scraping pages to make RSS feeds when they didn't have one already"... yeah, exactly.
I recently built a new OPML set of feeds from scratch, in different areas like Linux, ham radio, science, general news, and shopping/deals. Easily 95% of these sites offered RSS or Atom feeds. The main offenders were national news sites, for which there were plenty of alternatives.
Only a couple are available yet annoying, like the forum at eham.net, which offers a feed that essentially gets you unsorted forum replies mixed in with new topics. So every day's updates are full of "Re:" entries. Anyway that's been the only speed bump so far. I was surprised.
Also, since I monitor niche subreddits on Reddit, their generalized feed availability means I can automatically get amazingly wide access to a variety of niche topics (e.g. shorthand writing).
Part of my experiment was aimed at figuring out whether RSS is useful to me. It really is, though careful culling of unwanted or unneeded feeds is important. It's kind of like maintaining a plain-HTML links page. Still valuable in its simplicity, but also requiring ongoing refinements to continue to be useful.
yep RSS sure isn't the most user friendly solution, and i guess it's always been the problem #1 with RSS.
But it's getting better, or at least not worse?, there's now many good web-based RSS readers that do a great job at helping people find and subscribe to sources but it's still not facebook-easy.
The comment above where someone said "RSS isn't dead, I have a business scraping pages to make RSS feeds when they didn't have one already"... yeah, exactly.