Appeals power

I am looking at the news today saying 94% of eople appealing pip decisions are winning there case. Which is fantastic.
But I a also in the view that the assessments for someone decision should be done by someone with expertise on that person's condition ect.

These people are trained medically  but they need to be specialised in the area they are accessing in order to make a fair decision.

They are rarely specialised or knowledge of how it effects the person whom they are assessing. I think this is neglegence on behalf of DWP. If ahosital can be done for malpractice why are the DWP any different.