I find a lot of the popular stories are heavy on emotions, but low on facts. Most of them even have wrong facts, sometimes bordering on conspiracy theories. I have tried fact-checking them, but these stories get like no views. I would recommend having the ability to link stories on the same themes together (rebuttals or different points views, and fact-checks), so that you end up creating a conversation.
Medium used to be big on thoughtful articles on philosophy, science, history and other stuff. That's what attracted me in the first place. However, much of that has either disappeared or doesn't show up at all. Rather, what does show is shallow-thinking politics, how to make money on Medium, and various shallow-thinking doom and gloom stuff. What I would rather see promoted is the stuff that attracted me in the first place, and not the stuff a lot of writers focus on now.
I am also not too keen on publications. They do sometimes help, but they are often too restrictive. This means you are limited in the choice of topics you can write, the style you want to write in, but also don't have the ability for example to set when you publish your stories.