You ask here, "Do you need doors there?" Who is "you"? There can only be individual answers to that, which you also get here. For example, I never wanted to live so openly.
But there are objective truths that generally apply to people, even if not everyone may feel them equally strongly. We are prey animals. We feel safer with a wall behind us and an overview of where a saber-toothed tiger could be lurking.
That is probably the case with you too, but you apparently accept it in favor of your chic and fashionable staircase. That is perfectly fine, but if you ask, there are answers. Personally, I would feel like my sofa is standing in the stairwell, but maybe you use your living room quite differently than I do. For me, it is a very private retreat where I want to feel safe, unobserved, and cozy. What is it for you?