In their infinite wisdom, Apple has always stuck to the idea that they don’t want you messing with any of their stuff in any way. You are free to use it. You are free to upgrade or buy a new one, but they really don’t like the idea of you opening up their products to see what’s inside.
By making it as hard as possible for you to explore their devices, they can charge more for a replacement one. If you were to learn how to fix them, then their business model would fall apart overnight.
Yet there are Macbook repair shops out there. They have access to Apple certified parts and all the technical service bulletins needed to fix the things that go wrong with all types of digital devices. If they are unable to help you, Apple will still be there waiting for you to come crawling through the door.