Some past examples of art restoration have been horrendous, whereas nowadays the general trend is to fix the problems in such a way that the restoration work is visible (using certain special techniques if need be) to make it clear what is original, and to be reversible. Also, better materials are available nowadays.
Regarding the comments by IT specialists, it is worth bearing in mind that many systems get a complete rewrite after a time so that the functions are written more clearly and work better and faster. New tools and programming languages are an issue too, unless you are maintaining old COBOL programs on a mainframe. And some of them are still around.
There are many reasons for that. First of all, the second physician will have the benefit of the work up already completed by the first one, and also information as to whether or not the recommended interventions helped. There are also many things that could contribute to a negative outcome that have nothing to do with the abilities of the first physician. Treatment choices may have been limited by insurance. The patient may have not been compliant with the recommended treatments, missed a follow up, etc. The initially recommended medicine may have had side effects the patient could not tolerate, and so on.
There are many reasons any given patient’s outcome could be less than optimal, and the lack of ability of the patient’s previous physician is usually towards the bottom of the list.
I watched a show about a diamond cutter - a profession where a mistake can be extremely costly. When asked how much he learned as he went along he replied, "For the first 10 years I was terrified. For the 2nd ten years I thought I was the best diamond cutter in the world. For the 3rd ten years I realized I should have been terrified for the 2nd ten years:.
I’m not sure if politicians count but in a way they are both - nowadays, a politician in the opposite political party can do absolutely nothing right, but politicians (especially Republicans) will bend over backwards to excuse or dismiss any wrongdoing from their own party members.
Upon re-reading this, I wish to clarify something. I’m referring to the pilots hanging around my local airport, and instructors hanging around the flight school. I was not referring to our aviation experts on this forum. I apologize for the inadvertently broad brush.
Translators usually work alone, often at home, and end up thinking they are the very best in the world. In my experience when they read a colleague’s translation they seldom like it and say so clearly. Often they may be right but more often than not they express a matter of taste over something quite subjective.
As to interpreters, I once worked on a civil trial where almost everyone involved was Romanian, or Romanian-speaking. Each side brought its own interpreter for the court. By the end of the trial, the interpreters were arguing with each other over their respective interpretations!