NEW Wonderful Windows Concept Card Kit

Is there such thing as “too open concept?” One of the spaces I’ve been trying to make sense of since we moved here was this elongated living area- it’s never quite felt like one cohesive space and with one half being wider than the other made furniture placement tricky. After doing some investigating I found out:1. The door used to be an exterior door2. There were windows along the stair wall3. The open area for the stair case used to be 3 ft larger but was closed off to make a closet in the ups