Burnout isn't interesting to organizational psychologists because it was relatively well-understood in 90s. There's only so much you can study in this space and all the low-hanging fruit is gone. It's still a popular topic for some, but the reason you don't see the actual research is probably because you expect it to be covered in blogs. Go to a university library, get on the wifi, and download some proceedings of organizational and cognitive psychology journals.
that's why you would do a longitudinal study. Pick a cohort of individuals that are entering a high-risk-of-burnout field, and the control will be the pre-burnout individual and the experiment would be monitoring them over time. Of course this doesn't really fit funding/research promotion cycles in science.