Suppose that a drug can cure a very dangerous disease that many people suffer from, but it must also have side effects, or maybe few people will die for it, but in general it is good for society.
Will the doctor prescribe this medicine?
He has no reason to do so. Patients injured by side effects will haunt the doctor like a dog by a lawyer or the patient himself, and the rescued patient may never see him again.
Those who benefit are evidence of silence, and an absolute majority, but we cannot see or hear it, and one or two cases of side effects are enough to excite the news and the media for half a year.