The people who pay for operating systems are paying for a private entity to decide what the operating system should do. They're paying for someone to compile it

The people who pay for operating systems are paying for a private entity to decide what the operating system should do. They're paying for someone to compile it from source and get it to run on their computer and maintain it. That's the whole point. Paying someone for that thing you also know how to do so they can consider that problem solved and focus on the things they know how to do.