"91% Employees Experience Burnout" implies that 91% of employees suffer from burnout, whereas - firstly - there is no data in the article to indicate that this is the case.
Secondly, the question that comes closest to the 91% answer is "What is the main source of employee burnout at your current workplace?", to which 9.7% of people answered that "Burnout isn't a problem at my company." This leaves 90.3% (and a rounding error!) who think that burnout is a problem at their company and think they know why that is. This does not mean they themselves are suffering or have suffered from burnout.
I'm not trying to minimise the problem of burnout, but I would strongly suggest if we're going to have a serious discussion about it we should get our facts and our data straight and not base that discussion off a poorly written and researched employee engagement puff-piece.