Neither "the worst case would be" nor "everything is a sliding scale" are good single hueristics. There are rarely There are rarely good single hueristics, but implying them tends to color discussions strongly.
replyI've related self-dianoses of minor issues to a doctor, immediately followed up with a proviso that I don't put a lot of credence into non-professional opinions. The doctor was supportive that patient directed investigations had value. There is a threshold where an informed patient can be useful for treatment.
replyYeah, I personally know a couple people where self-research found the correct diagnosis, and I am one of them. We had a fantastic primary, who worked with us quite closely and did a lot of research after we found some new information from him.
replyDoctors don't know everything and don't have access to everything, they are just quite a lot better than the alternatives in the vast majority of cases, so your default odds are much better following their recommendation than anything else. Training is worth a lot, and everyone also knows it's not perfect, and that's entirely fine.