Medium's problem is that the posts just aren't that interesting. There are lot's of people that write well. But, yippeeeee, big deal. Sure there are people that elevate writing to an art form and regardless of the topic it will be worth reading. But most of the time it's a just form of communication and it's what's being communicated that counts. Medium has a quantity problem: the quantity of interesting posts/articles is low. Very low.