QOL is subjective in a sense that it depends on where. Do people in China feel their QOL is better that it was in the past? Russia? Iran? Some shithole in Africa?
People all too often see it subjectively as it relates to them. Is my quality of life better than it was for my parents? Yes in some ways and no in others but overall I'd say yes. I have access to comforts my parents didn't. I agree that creature comforts are only a part of QOL. There are other factors we could debate I'm sure.