I don't understand psychological tests at all. People who want to believe they are at risk of burnout will answer questions in that direction. Isn't the whole field an obvious sham?
On the other hand, you have the possibility of not lying and getting an useful answer. The difficulty of doing that varies, and the more objective the questions, the easier it is.
Did you have a counter argument to offer or?
Does the test perhaps make sure that there is sufficient agreement on the definition of burnout? Perhaps it ensures that someone doesn't just say they are burnt out because someone in their life told them they might be? Perhaps it helps people realize they have a burnout because they didn't know the definition? Perhaps it provides those who don't have a burnout with confidence that they don't?