If I remember correctly people said Medium is very limiting and confusing when it comes to ownership of your content.
It seems they can re-use (as in publish) your original content elsewhere, like publishing it in a book.
What I especially dislike is the registration enforcement (register! Use our App! Become a member!).
There are some sources in my feedreader from Medium and they become less and less usable.
Something I stumble upon more often recently is Substack. Actually intended to be a tool for offering paid content and a newsletter publishing tool, I think, but the user experience is much more pleasant. They ask me to subscribe to the publisher’s newsletter each time, but don’t prevent me from going further, if I decline.
Also getting some attention recently is the indieweb movement. People intentionally publish on their private websites, running on various different platforms and techniques. It’s quite interesting to observe and it seems there is a focus on a more tech-savvy audience and publisher group, but I might be wrong.