It's a common misconception that burnouts come from hard work.  Burnout comes from a felt loss of control and/or impact.  Remember that you can burn out employees (or yourself) with little to no work.

working theory: a lot of “burnout” is just the result of prolonged exposure to environments you were never truly aligned with to start

“Burnout” is a particularly modern affliction, feeling simultaneously overwhelmed and paralyzed. I’ve found it’s best to think of burnout not as a disease but as a symptom, with many different etiologies. The big three: permanent on-call, broken steering, and mission doubt.