This is especially true on macOS Catalina or later with SIP enabled. The entire operating system is mounted read-only [1] and your local changes are effectively

This is especially true on macOS Catalina or later with SIP enabled. The entire operating system is mounted read-only [1] and your local changes are effectively contained within your user directory. [1] https://support.apple.com/en-us/HT210650 https://support.apple.com/en-us/HT210650