I'm a total outsider to that side of things, so maybe someone can explain it to me.
I see a lot of blogs and interesting articles that are on Medium. What I don't get is why they are there. It doesn't seem to be any different than any other blog site, except maybe it look a bit nicer. But that doesn't seem to be enough to explain how so many things I read are on Medium.
Is it discovery? Because I've never browsed medium. I just look on HN, and yet again there's some article hosted on Medium. Or I land on it through some other aggregation site.
I'm not sure how I'd be interested in better discovery, either. There's enough stuff on the web to read, so unless their discovery is amazing (ie fits my interests without me having to spend time searching/configuring) I don't see what the point is.
To me, the uninitiated, it just looks like yet another place to put articles. And that's why it is kinda surprising to read that hundreds of millions of dollars have been invested.