You can make your own with Feedly feeds. I started using it after Firefox dropped RSS support. Got some news, HN, and niche topics in a custom feed.
Do we know how they decided how to size the various stories?
My friend and I have been working on this site http://feedvix.com that’s sort of similar. It’s a random mix of news articles, jeopardy questions, xkcd comics, Investopedia terms, jokes from the 80s, chemical elements, notable quotes, and Wikipedia articles. It’s good for when you run out of content from whatever you typically read.