A bunch of random feeds, some of which may be dead:
http://chainsawsuit.com/feed/
http://feeds2.feedburner.com/motherjones/BlogsAndArticles
http://feeds.feedburner.com/AtlanticBusinessChannel?format=xml
http://feeds.feedburner.com/Brentevans?format=xml
http://feeds.feedburner.com/EconomistsView
http://feeds.feedburner.com/seriouseats/recipes
http://feeds.feedburner.com/SeriousEats-thefoodlab?format=xml
http://feeds.feedburner.com/tapestrypearls
http://feeds.highgearmedia.com/?sites=GreenCarReports
http://phantomnitpicker.blogspot.com/atom.xml
http://rss.slashdot.org/Slashdot/slashdotLinux
https://archive.nytimes.com/opinionator.blogs.nytimes.com/category/the-conversation/feed/
https://blog.xkcd.com/feed/
https://feeds2.feedburner.com/AtlanticPoliticsChannel
https://feeds.feedburner.com/Inthedrops
https://feeds.feedburner.com/TheWirecutter?format=xml
https://feeds.npr.org/1001/rss.xml
https://feeds.washingtonpost.com/rss/linksets/opinions/editorials
https://fivethirtyeight.com/all/feed
https://hothardware.com/mobile/articles.aspx
https://insideevs.com/rss/articles/all/
https://krugman.blogs.nytimes.com/feed/
https://longform.org/feed.rss
https://nautil.us/rss/all
https://news.ycombinator.com/rss
https://pearlswine.livejournal.com/data/rss/
https://poorlydrawnlines.com/feed/
https://priceonomics.com/latest.rss
https://revealnews.org/feed/
https://rss.nytimes.com/services/xml/rss/nyt/EnergyEnvironment.xml
https://rss.nytimes.com/services/xml/rss/nyt/US.xml
https://rss.nytimes.com/services/xml/rss/nyt/World.xml
https://taskandpurpose.com/feeds/feed.rss
https://theconversation.com/us/articles.atom
https://theoatmeal.com/feed/rss
https://thisisindexed.com/feed/
https://tinyhouseblog.com/feed/
https://twitrss.me/twitter_user_to_rss/
https://velo.outsideonline.com/feed/?scope=anon
https://warontherocks.com/feed/
https://what-if.xkcd.com/feed.atom
https://wordpress.aje.aj-harbinger.com/feed
https://www.anandtech.com/rss/
https://www.badscience.net/feed/
https://www.military.com/rss-feeds/content?keyword=headlines&channel=news&type=news
https://www.nytimes.com/svc/collections/v1/publish/www.nytimes.com/column/david-brooks/rss.xml
https://www.nytimes.com/svc/collections/v1/publish/www.nytimes.com/column/paul-krugman/rss.xml
https://www.pbs.org/newshour/feeds/rss/headlines
https://www.propublica.org/feeds/propublica/main
https://www.snopes.com/feed/
https://www.theverge.com/rss/index.xml
https://www.tomshardware.com/feeds/all
https://www.vox.com/rss/index.xml
https://xkcd.com/rss.xml
I can see it just fine. (and I also use newsblur).