Great comment! I might be able to answer both of your questions with one word....agenda.
Once there is an established Idea or belief and it is pushed or encouraged for a social/financial type gain it needs to be questioned harder. That is even where doubt sets in, due to human actions and how they use information. If information is allowed to be information and we are still free to think what we want without exclusion or labeling, then it is wonderful. In all of my years studying metallurgy I have never read any biase or agenda behind the idea of metal or making alloys.
The idea of trusting an expert is completely up to the individual. There are many people that are considered experts in many things. We all choose who we enjoy following for the betterment of our lives.🙃
I like that. "Agenda" is a HUGE deciding factor on subjects. If there is an agenda, then it needs to be "under a microscope" for lack of a better term haha!
I come from the angle of "Is the person(s) more focused on their agenda and selling me something , are they just sharing a point of view, or am i reading/hearing something that, like you put it, without a bias or agenda?
The fog lifts when we have an analytical mind! Im glad you enjoyed my comment, it takes me a bit to get it out to where it makes sense sometimes. My brain is a million mile an hour machine that most normal people cant keep up hahahahaah!!!!