Back in the old days past, most manufactures of console stereos had open back cabinets. Some of these sounded really great and had no lack of bass.
In experimenting while building DYI speakers I found a properly damped cabinet with not fully open back but partial depending on the cabinet size can open up the sound stage. Allowing an internal pressure regulated to breathe. With a resonator port internal to the cabinet with part of the resonator end open in my case with a front vent also made a Smooth lower mid bass. Midbass woofers usually cross over at any number of frequencies depending on the woofer can cross over from 500 to 5,000 depending on the setup. The woofer also does mid range as well as bass. The tuned hemholz took charge of the deep frequencies. There are more factors than you can shake a stick at when building. But this worked in my case. I am not an expert by any means. However if open back is used properly I think it is rewarding. I just had fun. I suspect some higher end open back manufacters are striving for openness not sounding like a cabinet or case is there at all.