There are plenty of folks who have no issue with 'sitting on the floor', of course. But I do like having a chair. Just got back from a trip in the Sierra, went over Sawmill Pass and wandered a bit. Had my Helinox Ground Chair with me, and was happy to have it. It's the only thing I can sit in/on for any length of time due to pain in my lower back, so while not 'absolutely essential', it does help me enjoy backpacking more.