Sorry medium, this is a design problem. If your GUI doesn’t clearly communicate the separation of different posts, you should fix your gui, not limit useful formatting features as a bandaid.
While I do like how clean medium is, you’ve taken things a bit far with the lack of visual structure in your design. Things feel like they’re arbitrarily floating in the middle of some empty space because there is no visual structure to frame their presence.
It seems lack of differentiation between one post and another is example of this problem.