Having a phone stop working on you is perhaps a nightmare that a lot of people go through. Especially those who rely on their phones for a lot and I am saying this because I have been through this and well, it is important that if you are hiring someone who is a professional, they know what they are doing because it is very important that the service is good enough.
Again, you can check Samsung repair shop and be sure that the person working on your phone is qualified enough because you really do not want anyone random to handle things for you. As long as you are taking care of these things, I doubt anything will be getting out of hand.
They Have The Tools Required
Gone are the days when you could just open the phone on your own without needing specialized tools but that is no longer the case as you would need to have access to tools that are specialized and without those. The more you are aware of this, the better it is for your phone and ultimately, you.
Years of Experience
Another thing is that they have years of experience that they have used time and again to ensure that everything is handled the right way. If you are worried something might not work the right way, you just look into that and you will be all sorted in no time. Just focus on it and it will not take you as much time, either.
Again, it varies from service to service and the more you look into it, the better it would be for everyone.