Why is 'sudo' required? Just curious. I moved away from homebrew, to compiling my own software on macOS which I just put in ~/build. I don't use sudo make inst

Why is 'sudo' required? Just curious. I moved away from homebrew, to compiling my own software on macOS which I just put in ~/build. I don't use sudo make install since I own the ~/build folder. What am I doing wrong in this case?