I believe that autistic burnout is something that other people do to us rather than something we do to ourselves.
It's not simply that we mask too much or work too hard; society requires us to do those things. The choice is not ours.
Those are not the only things that cause burnout. Bigotry and abuse from others also causes burnout. Constant sensory Hell also causes burnout. Anything that keeps us out of equilibrium causes burnout.