Earlier quoted context omitted.
Also keep in mind that you get hip replacement surgery because of constant, quite intense, pain. The doctors obviously also talked to the patient and he or she obviously felt that just reducing the pain was worth the risk (because a replacement hip will still be long-term painful, so it's an improvement, not a solution. This will have been discussed extensively with the patient) ... Or the patient may even have felt…
Quite frankly, no one expects that and that is not where the disappointment comes from. The disappointment comes from the fact that doctors are mostly clueless and follow checklists, and thus prescribes measures without having a deep understanding (or interest even) of the situation. Why? Because these people (doctors) were never curious to begin with. 99% of the never cared to understand biology before they started…
Trying medicine because "you've heard that ..." is a fancy way to commit suicide, or worse. And yes, a great deal of people want to do that, until of course, they have to face the consequences. Then they want it fixed, except there is no fix. No doctor should want to be part of that, and these Chinese "researchers" should be made to answer for manslaughter for what they did.
Surely the story we're talking about illustrates this problem? For all we know the gene-editing worked! That was NOT the problem that killed the girl. Congrats, your "curiosity-based treatment" would have made the girl 10% smarter in 10 years. Probably. Unfortunately, she's dead in less than a week. Congratulations!
Is that REALLY something you'd like to hear about anyone you know? Would that satisfy your curiosity? Big risks, even ones your not aware of, are NOT a reasonable price for trying out medical treatments.