Here’s one of the easiest ways to explain it.
When you go to get your check engine light would you prefer the technician to look at the light and say:
Well, sometimes this means you need a new engine so let me just go ahead and get that started for you it’s going to be $5000, will you be paying cash or credit today?
This is usually no big deal, I’ll just change your oil and if it comes back, don’t worry it is probably a broken light sensor, not a problem. Just bring it back again.
Or would you prefer if your technician popped the hood and used the tools available to figure out the problem and make a diagnosis of the underlying cause of the problem?
You’d probably want to actually get to the bottom of the issue, right? Your health is important. You want as much information as possible before you go all in on big treatments like surgery, or continue to just cover up the problem with pain medication that you have to keep going back for.