Actually, it's a lot more than that. It's the fact that we have the capability to treat many more diseases than in years past. There are more choices to make. The amount of learning required has induced increased specialization, which narrows the solution set offered by any one practitioner, often to the point of unapplicability. The amount to learn also decreases the pool of qualified physicians. Doctors want to cure patients, so they try their best within their knowledge. Unfortunately, maladies aren't specialized.
Advanced capability in any specialty often comes at a higher price. That combination increases risk. Pooling risks increases the total that can be spent on any one case, which gradually increases total demand beyond what the payer can bear. The pressure to cut costs increases, as does the risk that the diagnosis is wrong.
Taken together, that means doing more in less time. There are now more "correct" diagnoses requiring more data than can be determined in the time and budget alotted for initial screening.
You couldn't be more correct! It's all about information overload and the rest of the stuff you described so well!!!