Ok...fine the first two stages can be skipped. Some people might have low adrenal function all their lives.
That really doesn't change the fact that many others can and do go through the 3 stages.
The AF forum is full of former high energy people. They often went through periods of being able to handle more stress than normal. (adaptation...or Stage 2).
then.... all of a sudden, they can handle less stress than normal.
it is a very common pattern amongst the forum members. It is so common to see newbies show up and say " I worked out every day for years and now I have no energy".
It is the same pattern that Hans Selye observed over and over. His work is still in medical texts to this day.