It has been said that a good paramedic knows when to go balls to the wall on a code and when to slow walk and go through the motions on resuscitation efforts. I could not handle that choice.
My wife was a nurse and department head. The last multi-level skilled facility she worked at, she had one of my coworkers (who was an amazing paramedic who later became one of the assistant cheifs) come in and talk to the residents about DNR (do not resuscitate) paperwork. He explained to them the injuries that properly administered CPR does to the body of elderly patients and the likelihood that they will make a full recovery.
On the department that I worked for I was aware of no decision making process as you described where anyone received less effective CPR or defibrillation. The difference in CPR is that when someone is very fragile, we tried to be more gentle. On that type of person you can feel their ribs crunching and breaking loose from their sternum.
Normally people receiving chest compressions are unconscious, but we frequently assist the breathing with a bag valve mask on conscious patients. Our protocol was for everyone to receive the same amount of effort and I never was aware of any conscious decision making process by any of the paramedics or firefighters that I worked with based on their opinion of the likely long term outcome.
That said... their are huge differences in the abilities of paramedics and firefighters. The hands down worst person that I ever worked with was the head of our union. Because of his position he repeatedly got away with incompetence and malfeasance that put our department in severe legal jeopardy.
Government employee unions ensure that services provided will always be second rate... This is true in firefighting, policing, education, utilities, building departments, and health-care. Despite sincere efforts by dedicated individuals, the unions protect the incompetent, untrustworthy and even evil ones from being held responsible for their actions and this drags down the quality and consistency of services being provided.