I feel they should clarify what they mean, and what respondents meant, by 'burnout'. Burnout is an extreme state and I am extremely surprised that 83% would feel that way.

From the actual study "A total of 83% of Software Engineers reported feelings of burnout with only 17% reporting no burnout. 55%, a majority, reported “great” or “moderate” levels of burnout."

What is a "moderate level of burnout"? This is self-contradictory, so I'm not convinced that respondents really meant 'burnout' in the strict sense, and the question itself leads to this lack of clarity.